Update astroid to 0.15
Update astroid to 0.15. Now that scdoc is in the repo, we can build the man page with it.
- Faster editing of tags
- Number of bug fixes
- Lots more, check the git log!
Test Plan: as before, open astroid, read and search a few emails with English and Chinese text.
Reviewers: Triage Team, JoshStrobl
Reviewed By: Triage Team, JoshStrobl
Subscribers: Jacalz, JoshStrobl
Differential Revision: https://dev.getsol.us/D6798