Add Support for https://login.gci.com/ Adobe SSO

[The-OMG]

• I've verified and I assure that I'm running youtube-dl 2018.03.26.1

Before submitting an issue make sure you have:

• At least skimmed through the README, most notably the FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones
• Checked that provided video/audio/playlist URLs (if any) are alive and playable in a browser

What is the purpose of your issue?

• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
• Other

I would appreciate assistance in adding support for the cable provider "GCI". With paid cable services they offer access to various apps and content websites just like most other cable providers.

Their page showing what a paid user can access can be found here:
https://www.gci.com/tv/tv-everywhere/now-available

I have my login that I can give out for testing. My account has full access to every cable service offered on their plan page above.

I can be reached at omg@orionsbelt.space

Thank you for your time.