Use standard gemfile with version pins

Gemfile

@@ -1,28 +1,27 @@
 source 'https://rubygems.org'
 
 group :lint do
-  gem 'foodcritic'
+  gem 'foodcritic', '~> 4.0'
-  gem 'rubocop'
+  gem 'rubocop', '~> 0.33'
+  gem 'rake'
 end
 
 group :unit do
-  gem 'berkshelf'
+  gem 'berkshelf',  '~> 3.2'
-  gem 'chefspec'
+  gem 'chefspec',   '~> 4.3'
 end
 
 group :kitchen_common do
-  gem 'test-kitchen'
+  gem 'test-kitchen', '~> 1.4'
 end
 
 group :kitchen_vagrant do
-  gem 'kitchen-vagrant'
+  gem 'kitchen-vagrant', '~> 0.18'
 end
 
 group :kitchen_cloud do
   gem 'kitchen-digitalocean'
   gem 'kitchen-ec2'
-  gem 'kitchen-joyent'
-  gem 'kitchen-gce'
 end
 
 group :development do
@@ -37,4 +36,4 @@ group :development do
   gem 'rake'
   gem 'fauxhai'
   gem 'pry-nav'
-end
+end