Add new "single_run" rake task
Add new "single_run" rake task

The task is supposed to correct the mapping of current season's
applications' and application_drafts' projects to projects from the
current season.

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