fix rubocop errors.

1 files changed, 2 insertions, 0 deletions

diff --git a/Gemfile b/Gemfile
index cc220b4..f396f5d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
 git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }