Add task to remap mentor-sign-offs
Add task to remap mentor-sign-offs

The task remaps old-style mentor sign-offs to the respective project
within the application.

TeamCheesy/rgsoc-teams,rails-girls-summer-of-code/rgsoc-teams,michaelem/rgsoc-teams,TeamCheesy/rgsoc-teams,michaelem/rgsoc-teams,michaelem/rgsoc-teams,rails-girls-summer-of-code/rgsoc-teams,rails-girls-summer-of-code/rgsoc-teams,TeamCheesy/rgsoc-teams