Migrate to gitlab

[emthompson-usgs]

Need to:

• Clone repo to gitlab
• Remove all c/cython
• Remove usernames from documentation
• Remove links to azure in readme
• Gitlab repo needs to be released
• Add link to gitlab url in readme
• Indicate new repo urls in documentation.
• Update the doi link to point to gitlab
• Migrate issues to gitlab
• Archive github repo

[emthompson-usgs]

I think we are getting pretty close to moving to gitlab. Also, I'm thinking some of these steps are overkill. For groundfailure, we just sent in a merge that deletes everything except the readme (and some of the admin files) and modified the readme to point to the new repo in gitlab. This seems like a reasonable and easier approach.

[gferragu]

@emthompson-usgs the re-designation as a read-only public archive is a nice Github feature, does a warning get printed if you try interacting with the archived remote from the CLI?

[emthompson-usgs]

It does not appear that there is a warning. However, I think that the fact that all functional code has been removed from the repo would prevent anyone from accidentally continuing to use it.