added api for downloads. Close #164
Merge branch 'refs/heads/master' into features/api/downloads
added Relase.pre_release to ReleaseResource
added gpg_signature_file field to ReleaseFileResource
moved API urls out of the way
added calendar links to events sidebar. Close #109
added migration
Merge pull request #200 from fcurella/features/api/downloads

added api for downloads. Close #164
Merge pull request #212 from fcurella/bugfix/events-subscribe

added calendar links to events sidebar. Close #109