Add validation to github organization string

[delucchi-cmu]

Change Description

We added this field mostly to create valid hyperlinks, and if the string is invalid, that's no good for anyone!

Checklist

• This PR is meant for the lincc-frameworks/python-project-template repo and not a downstream one instead.
• This change is linked to an open issue
• This change includes integration testing, or is small enough to be covered by existing tests

[camposandro]

Looks good! Out of curiosity, is there any official GitHub naming convention for the repositories and organizations? I tried to look it up online but didn't find anything relevant.

[delucchi-cmu]

Great point - and I should have checked first =]

I also couldn't find any resources, but I tried to create a new repo with some weird characters, and the UI helpfully told me the requirements (for repo names):

The repository name can only contain ASCII letters, digits, and the characters ., -, and _.

I tried bad &&++name with space with a response of Your new repository will be created as bad-name-with-space. So the validation for repo names isn't consistent with the actual naming requirements on github, which seems non-ideal.

[delucchi-cmu]

Thought about it again, and though our validation is stricter than the real package naming requirements of github, they're closer to (and laxer than) the PEP423/PEP8 recommendations for module/package names. So I think I'm going to count this as done.

[camposandro]

Interesting! I think alphanumeric strings separated by dashes or underscores accommodates what most people use anyway. I guess it's best to have some validation than to have none and at least we prevent having an empty input.