Subject should be serverspec resource type class

In #325, I wrote "Custom matchers should not check the subject class".

But it's not correct.

Custom matchers should check the class of the argument of match block.

I use ``subject`` as the argument name and it is same as the method name
with RSpec.So it's confusing.

I should not use the name ``subject``, but keep them tentatively.
Merge pull request #326 from serverspec/subject-should-be-resource-type-class

Subject should be serverspec resource type class
Define user and group methods explicitly in Serverspec::Type::Process

Because user and group methods are defined already in Serverspec::Helper::Type.
So method_missing is not called if these methods are not defined explicitly.
Add spec.
Merge pull request #330 from serverspec/explicit-methods-in-process-type

Define user and group methods explicitly in Serverspec::Type::Process
Bump up version
Fix spec for specinfra v0.4.1
Move spec/backend/exec/build_command_spec.rb to specinfra
Merge pull request #331 from hanazuki/move-backend-test

Move spec/backend/exec/build_command_spec.rb to specinfra
Change regex to match more vagrant machine names

Support machine name that contains digits or uppercase letters.
Merge pull request #334 from kaorimatz/vagrant-machine-name-regex

Change regex to match more vagrant machine names
Bump up version
Fix to spec_helper to use SpecInfra::CommandResult
Fix to use SpecInfra::CommandResult
Merge pull request #338 from serverspec/fix-to-use-specinfra-command_result

 [WIP] Fix to use SpecInfra::CommandResult
Bump up version and specinfra version dependency
Add create_release task
Fix to work without octokit
Fix syntax error for Ruby 1.8.7
Merge pull request #339 from nishigori/fix-hash-arguments-syntax

Fix syntax error for Ruby 1.8.7