[COOK-4271] Add ability in pip lwrp to send custom env vars

Author: petecheslock

providers/pip.rb

@@ -151,7 +151,10 @@ def remove_package(version)
 
 def pip_cmd(subcommand, version='')
   options = { :timeout => new_resource.timeout, :user => new_resource.user, :group => new_resource.group }
-  options[:environment] = { 'HOME' => ::File.expand_path("~#{new_resource.user}") } if new_resource.user
+  environment = Hash.new
+  environment.merge!({ 'HOME' => ::File.expand_path("~#{new_resource.user}") }) if new_resource.user
+  environment.merge!(new_resource.environment) if new_resource.environment
+  options[:environment] = environment
   shell_out!("#{which_pip(new_resource)} #{subcommand} #{new_resource.options} #{new_resource.package_name}#{version}", options)
 end
 

resources/pip.rb

@@ -34,3 +34,4 @@ def initialize(*args)
 attribute :user, :regex => Chef::Config[:user_valid_regex]
 attribute :group, :regex => Chef::Config[:group_valid_regex]
 attribute :options, :kind_of => String, :default => ''
+attribute :environment, :kind_of => Hash, :default => {}