Pin neutron gem versions for stable branch

This intends to pin all the major gems to the version they were during
development cycle.  This should isolate the existing tests from changes in
rspec, etc.

Partial-Bug: 1326034
Change-Id: I17ffd9255de6e04d0b036fa9466bf59171b1a762

Gemfile

@@ -3,10 +3,13 @@ source 'https://rubygems.org'
 gem 'json'
 
 group :development, :test do
-  gem 'puppetlabs_spec_helper', :require => false
+  gem 'puppetlabs_spec_helper', '~> 0.4.1', :require => false
+  gem 'rspec', '~> 2.14.0'
+  gem 'mocha', '~> 0.10.5'
+  gem 'rspec-puppet', '~> 1.0.1'
   gem 'puppet-lint', '~> 0.3.2'
   gem 'rake', '10.1.1'
-  gem 'webmock'
+  gem 'webmock', '~> 1.18.0'
 end
 
 if puppetversion = ENV['PUPPET_GEM_VERSION']