Gemfile in rbnacl-5.0.0 vs Gemfile in rbnacl-6.0.0

@@ -1,17 +1,18 @@
+# frozen_string_literal: true
+
 source "https://rubygems.org"
 
 gemspec
 
 group :development do
   gem "guard-rspec"
 end
 
 group :test do
-  gem "rspec"
-  gem "rubocop", "0.46.0"
   gem "coveralls", require: false
-  gem "rbnacl-libsodium", ENV["LIBSODIUM_VERSION"]
+  gem "rspec"
+  gem "rubocop", "= 0.60.0"
 end
 
 group :development, :test do
   gem "rake"
 end