pass provider into the feature checking powershell
added documentation for different providers
add be_version to the file resource for checking the metadata of a windows file
Merge pull request #344 from elmundio87/windows-file-version

Check the Windows metadata version of a file
Merge pull request #343 from elmundio87/windows-feature-providers

Windows feature: Search using different providers
Update dependency for specinfra
Bump up version
use its(:content) at a sample spec

it uses `its(:content)` instead of contain like http://serverspec.org/resource_types.html#file
Merge pull request #347 from serverspec/fix-sample-spec

use its(:content) at a sample spec