Update all old edx.org GitHub links to Open edX GitHub links in our codebase

[sarina]

• Once all the repos are moved, we need to update the old GH links to the new ones
• We need to make sure none of this breaks edx.org

@feanil @nedbat is there a timeline for this?

[ormsbee]

[Speculation]: This might become more urgent is edX decides to go with a fork + sync model.

[jmakowski1123]

Target Q2

[sarina]

This seems pretty straightforward with the right script. want to confirm that no one's done this yet.

[sarina]

I wrote a script to do this and will be running it as it seems to be working. Everyone will get tagged. Sorry not sorry

[sarina]

note: messed a thing up, once all these are merged will need do one final pass for the uses: edx/.github string but on a new branch name.

also ugh github.com/repos/edx/ (for API strings)

any instances of openedx/testeng-ci that I missed (that repo still in /edx/ org)

another:

[individual contributor's agreement](http://code.edx.org/individual-contributor-agreement.pdf)
[individual contributor's agreement](https://openedx.org/cla)

git clone git@github.com:edx/ -- already fixed paragon

[sarina]

87% of PRs are merged. Remaining 26 will be dealt with as part of the follow-up task #386