Moving the Environment Resource to Open-Source xEnvironment

[kwirkykat]

xEnvironment is an open-source copy of the in-box Environment resource.
Tests and an example have been added.

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This change is

[kwirkykat]

Remaining test failure is due to PSSA errors in existing resources.
#129 and #131 are already filed to address these issues.

[PlagueHO]

@kwirkykat - I fixed all the PSSA errors with PR #123. So once that is merged you should be able to trigger a dummy commit on this PR to resolve the AppVeyor failure.

[vors]

@PlagueHO @kwirkykat should be able to trigger re-build without dummy commit, directly from appveyor.

I tried to figure out how to enable it for non-powershell org members, but AppVeyor doesn't support it out-of-the-box http://help.appveyor.com/discussions/questions/2288-how-i-can-allow-anybody-trigger-a-re-build-on-a-public-project

[PlagueHO]

@vors - no worries 😄 I'm OK with doing dummy commits every now and then. I forgot @kwirkykat could issue them directly.