Fixes bug 910350 Add function to fix permissions on tables
* Created socorro.lib.migrations for useful utilities
* Moved CITEXT and JSON types into socorro.lib as well
Fixes based on webdev bootcamp styleguide
Refactor list comprehension (bah) and update alembic README r=@lonnen,@peterbe,@ErikRose
Merge pull request #1472 from selenamarie/bug910350-table-permission-reset

Fixes bug 910350 Add function to fix permissions on tables