Added super_diff gem for improved diffing in tests (#953)

Author: numbata

CHANGELOG.md

@@ -3,6 +3,7 @@
 #### Features
 
 * your contribution
+* [#953](https://github.com/ruby-grape/grape-swagger/pull/953): Added super_diff gem for improved diffing in tests - [@numbata](https://github.com/numbata)
 
 #### Fixes
 

Gemfile

@@ -45,4 +45,5 @@ end
 
 group :test do
   gem 'simplecov', require: false
+  gem 'super_diff', require: false
 end

spec/spec_helper.rb

@@ -20,6 +20,8 @@
 require 'rack'
 require 'rack/test'
 
+require 'super_diff/rspec'
+
 RSpec.configure do |config|
   require 'rspec/expectations'
   config.include RSpec::Matchers