Add Support for Github Enterprise Administration

[michaelsainz]

Hi all! I wanted to introduce myself to people here and announce my support for this project. I'm Michael Sainz, you can find out more about me here!

I am going to be opening up some PR's soon with some new functionality around interacting with our on-premise solution - Github Enterprise. You can read more about it here.

Here are some of my thoughts -

• [ ] Adding support for creation of Organizations
• [ ] User Administration
• [ ] Team Administration
• [ ] Repository Migrations

I would be most thankful for reviews and critiques of this code to ensure it maintains the high standard of this project and the PowerShell community as a whole.

[felixfbecker]

Support for Enterprise landed in v0.15.192 :)