Explicitly include irb via rubygems

Author: ianfixes

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Extraction of byes usage in a compiled sketch is now calculated in a method: `ArduinoBackend.last_bytes_usage`
 - Added ```nano_every``` platform to represent ```arduino:megaavr``` architecture
 - Working directory is now printed in test runner output
+- Explicitly include `irb` via rubygems
 
 ### Changed
 - We now compile a shared library to be used for each test.

Gemfile

@@ -6,6 +6,7 @@ git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 gemspec
 
 gem "bundler", "> 1.15", require: false, group: :test
+gem "irb", "~> 1.3.5", require: false
 gem "keepachangelog_manager", "~> 0.0.2", require: false, group: :test
 gem "rspec", "~> 3.0", require: false, group: :test
 gem 'rubocop', '~>1.5.0', require: false, group: :test

SampleProjects/TestSomething/Gemfile

@@ -1,2 +1,3 @@
 source 'https://rubygems.org'
 gem 'arduino_ci', path: '../../'
+gem "irb", "~> 1.3.5", require: false