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diff --git a/vendor/github.com/jzelinskie/stringz/stringz.go b/vendor/github.com/jzelinskie/stringz/stringz.go
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+// Copyright 2019 Jimmy Zelinskie
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package stringz implements a collection of utility functions for
+// manipulating strings and lists of strings.
+package stringz
+
+import (
+	"errors"
+	"strings"
+)
+
+// ErrInconsistentUnpackLen is returned when Unpack is provided two slices
+// without the same length.
+var ErrInconsistentUnpackLen = errors.New("the length of the unpacked is not equal to the provided input")
+
+// SliceContains returns true if the provided string is in the provided string
+// slice.
+func SliceContains(ys []string, x string) bool {
+	for _, y := range ys {
+		if x == y {
+			return true
+		}
+	}
+	return false
+}
+
+// SliceIndex returns the index of the first instance of x in ys, or -1 if it
+// is not present.
+func SliceIndex(ys []string, x string) int {
+	for i, y := range ys {
+		if x == y {
+			return i
+		}
+	}
+	return -1
+}
+
+// Dedup returns a new slice with any duplicates removed.
+func Dedup(xs []string) []string {
+	set := make(map[string]struct{}, 0)
+	ys := make([]string, 0, len(xs))
+	for _, x := range xs {
+		if _, alreadyExists := set[x]; alreadyExists {
+			continue
+		}
+		ys = append(ys, x)
+		set[x] = struct{}{}
+	}
+
+	return ys
+}
+
+// DefaultEmpty returns the fallback when val is empty string.
+//
+// This function is inspired by Python's `dict.get()`.
+func DefaultEmpty(val, fallback string) string {
+	return Default(val, fallback, "")
+}
+
+// Default returns a fallback value when the provided value is equal to any
+// of the zero values.
+func Default(val, fallback string, zeroValues ...string) string {
+	for _, zeroValue := range zeroValues {
+		if val == zeroValue {
+			return fallback
+		}
+	}
+
+	return val
+}
+
+// SliceEqual returns true if two string slices are the same.
+// This function is sensitive to order.
+func SliceEqual(xs, ys []string) bool {
+	if len(xs) != len(ys) {
+		return false
+	}
+
+	for i, x := range xs {
+		if x != ys[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
+// MatrixEqual returns true if two [][]string are equal.
+// This function is sensitive to order.
+func MatrixEqual(xs, ys [][]string) bool {
+	if len(xs) != len(ys) {
+		return false
+	}
+
+	for i, x := range xs {
+		if !SliceEqual(x, ys[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// TrimPrefixIndex trims everything before the provided index.
+func TrimPrefixIndex(s, index string) string {
+	i := strings.Index(s, index)
+	if i <= 0 {
+		return s
+	}
+	return s[i+len(index):]
+}
+
+// TrimSurrounding returns a string with both a prefix and suffix trimmed from
+// it.
+//
+// Do not confuse this with strings.Trim() which removes characters in a cutset
+// rather than working on prefixes and suffixes.
+func TrimSurrounding(s, surrounding string) string {
+	s = strings.TrimPrefix(s, surrounding)
+	return strings.TrimSuffix(s, surrounding)
+}
+
+// SliceMap is a functional-style mapping function for slices of strings.
+//
+// This is particularly useful when you would normally use a for-loop, but want
+// `defer` to execute for each iteration.
+func SliceMap(xs []string, fn func(string) error) error {
+	for _, x := range xs {
+		err := fn(x)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Join is strings.Join, but variadic.
+func Join(prefix string, xs ...string) string { return strings.Join(xs, prefix) }
+
+// CopyStringMap returns a new copy of a map of strings.
+func CopyStringMap(xs map[string]string) map[string]string {
+	// Zero allocation path.
+	if xs == nil {
+		return nil
+	}
+
+	ys := make(map[string]string, len(xs))
+	for k, v := range xs {
+		ys[k] = v
+	}
+	return ys
+}
+
+// Unpack assigns a slice into local variables.
+func Unpack(xs []string, vars ...*string) error {
+	if len(xs) != len(vars) {
+		return ErrInconsistentUnpackLen
+	}
+	for i, x := range xs {
+		*vars[i] = x
+	}
+	return nil
+}
+
+// SplitExact splits the string `s` into `len(vars)` number of strings and
+// unpacks them into those vars.
+//
+// Returns ErrInconsistentUnpackLen if len(vars) doesn't match the number of
+// split segments.
+func SplitExact(s, sep string, vars ...*string) error {
+	exploded := strings.Split(s, sep)
+	return Unpack(exploded, vars...)
+}
+
+// SplitInto splits the string `s` into `len(vars)` number of strings and
+// unpacks them into those vars. If there are more substrings that would be
+// split after len(vars), they will be all be put into the final variable.
+//
+// Returns ErrInconsistentUnpackLen if len(vars) is greater than the number
+// of split substrings.
+func SplitInto(s, sep string, vars ...*string) error {
+	exploded := strings.SplitN(s, sep, len(vars))
+	return Unpack(exploded, vars...)
+}
+
+// SlicePermutations returns all permutations of a string slice.
+//
+// It is equivalent to `SliceCombinationsR(xs, len(xs))`.
+func SlicePermutations(xs []string) [][]string {
+	return SlicePermutationsR(xs, len(xs))
+}
+
+// SlicePermutationsR returns successive r-length permutations of elements in
+// the provided string slice.
+//
+// If r is less than 0 or larger than the length of the pool, nil is returned.
+//
+// The permutation tuples are emitted in lexicographic ordering according to
+// the order of the input iterable. So, if the input iterable is sorted, the
+// combination tuples will be produced in sorted order.
+//
+// Elements are treated as unique based on their position, not on their value.
+// So if the input elements are unique, there will be no repeat values in each
+// permutation.
+//
+// This is the algorithm used in Python's itertools library:
+// itertools.permutations(iterable, r=None)
+func SlicePermutationsR(pool []string, r int) [][]string {
+	if r <= 0 || pool == nil || r > len(pool) {
+		return nil
+	}
+	n := len(pool)
+
+	indices := make([]int, n)
+	for i := range pool {
+		indices[i] = i
+	}
+
+	var ys [][]string
+
+	{
+		var y []string
+		for _, i := range indices[:r] {
+			y = append(y, pool[i])
+		}
+		ys = append(ys, y)
+	}
+
+	cycles := make([]int, n-(n-r))
+	for i := range cycles {
+		cycles[i] = n - i
+	}
+
+	for {
+		broke := false
+
+		for i := r - 1; i >= 0; i-- {
+			cycles[i] = cycles[i] - 1
+			if cycles[i] == 0 {
+				indices = append(indices[:i], append(indices[i+1:], indices[i:i+1]...)...)
+				cycles[i] = n - i
+			} else {
+				j := cycles[i]
+				indices[i], indices[len(indices)-j] = indices[len(indices)-j], indices[i]
+
+				var y []string
+				for _, i := range indices[:r] {
+					y = append(y, pool[i])
+				}
+				ys = append(ys, y)
+
+				broke = true
+				break
+			}
+		}
+		if !broke {
+			return ys
+		}
+	}
+}
+
+// SliceCombinationsR returns r-length subsequences of elements from the
+// provided string slice.
+//
+// If r is less than 0 or larger than the length of the pool, nil is returned.
+//
+// The combinations are emitted in lexicographic ordering according to the
+// order of the input iterable. So, if the input iterable is sorted, the
+// combination tuples will be produced in sorted order.
+//
+// Elements are treated as unique based on their position, not on their value.
+// So if the input elements are unique, there will be no repeat values in each
+// combination.
+//
+// This is the algorithm used in Python's itertools library:
+// itertools.combinations(iterable, r)
+func SliceCombinationsR(pool []string, r int) [][]string {
+	if r <= 0 || pool == nil || r > len(pool) {
+		return nil
+	}
+	n := len(pool)
+
+	indices := make([]int, r)
+	for i := range indices {
+		indices[i] = i
+	}
+
+	var ys [][]string
+
+	{
+		var y []string
+		for _, j := range indices {
+			y = append(y, pool[j])
+		}
+		ys = append(ys, y)
+	}
+
+	for {
+		var i int
+		broke := false
+		for i = r - 1; i >= 0; i-- {
+			if indices[i] != i+n-r {
+				broke = true
+				break
+			}
+		}
+		if !broke {
+			return ys
+		}
+
+		indices[i] = indices[i] + 1
+		for j := i + 1; j < r; j++ {
+			indices[j] = indices[j-1] + 1
+		}
+
+		var y []string
+		for _, j := range indices {
+			y = append(y, pool[j])
+		}
+		ys = append(ys, y)
+	}
+}
+
+// SliceCombinationsWithReplacement returns r-length subsequences of elements
+// from the provided string slice allowing individual elements to be repeated
+// more than once.
+//
+// If r is less than 0 or larger than the length of the pool, nil is returned.
+//
+// The combination tuples are emitted in lexicographic ordering according to
+// the order of the input iterable. So, if the input iterable is sorted, the
+// combination tuples will be produced in sorted order.
+//
+// Elements are treated as unique based on their position, not on their value.
+// So if the input elements are unique, the generated combinations will also be
+// unique.
+//
+// This is the algorithm used in Python's itertools library:
+// itertools.combinations_with_replacement(iterable, r)
+func SliceCombinationsWithReplacement(pool []string, r int) [][]string {
+	if r <= 0 || pool == nil || r > len(pool) {
+		return nil
+	}
+	n := len(pool)
+
+	indices := make([]int, r)
+	var ys [][]string
+
+	{
+		var y []string
+		for _, j := range indices {
+			y = append(y, pool[j])
+		}
+		ys = append(ys, y)
+	}
+
+	for {
+		var i int
+		broke := false
+		for i = r - 1; i >= 0; i-- {
+			if indices[i] != n-1 {
+				broke = true
+				break
+			}
+		}
+		if !broke {
+			return ys
+		}
+
+		newIndices := make([]int, r-i)
+		for j := range newIndices {
+			newIndices[j] = indices[i] + 1
+		}
+		indices = append(indices[:i], newIndices...)
+
+		var y []string
+		for _, j := range indices {
+			y = append(y, pool[j])
+		}
+		ys = append(ys, y)
+	}
+}
+
+// LastCut slices s around the last instance of sep,
+// returning the text before and after sep.
+//
+// The found result reports whether sep appears in s.
+// If sep does not appear in s, LastCut returns s, "", false.
+func LastCut(s, sep string) (before, after string, found bool) {
+	if i := strings.LastIndex(s, sep); i >= 0 {
+		return s[:i], s[i+len(sep):], true
+	}
+	return s, "", false
+}