drop mock dependency

mock is not used anywhere in the module, let's drop it.
This patch will help to hit this bug:
https://launchpad.net/bugs/1492636

Change-Id: I067f8c327635880c0fe46fc66c4c515f99070ff0
(cherry picked from commit ec9f7d095e)

Gemfile

@@ -13,7 +13,6 @@ group :development, :test do
   gem 'puppet-lint-variable_contains_upcase', :require => 'false'
   gem 'puppet-lint-numericvariable',          :require => 'false'
   gem 'json',                                 :require => 'false'
-  gem 'webmock',                              :require => 'false'
 end
 
 group :system_tests do

spec/spec_helper.rb

@@ -1,6 +1,5 @@
 require 'puppetlabs_spec_helper/module_spec_helper'
 require 'shared_examples'
-require 'webmock/rspec'
 
 RSpec.configure do |c|
   c.alias_it_should_behave_like_to :it_configures, 'configures'