Expand the list of valid tarball content types
Expand the list of valid tarball content types

The existing community site has no validation on content type, so the
following content types exist in the database:

* application/x-gzip
* application/gzip
* application/octet-stream
* application/x-tar
* application/x-compressed-tar
* application/x-gtar
* application/x-bzip2
* application/gzipped-tar
* application/x-compressed
* application/download
* application/x-gtar-compressed
* application/zip
* application/x-bzip
* application/x-zip-compressed
* application/cap
* application/x-tar-gz

We can impose validation going forward, but in order to import the
existing community site data, we'll need to relax our constraints.

nellshamrell/supermarket,juliandunn/supermarket,rafaelmagu/supermarket,rafaelmagu/supermarket,juliandunn/supermarket,dpnl87/supermarket,chef/supermarket,dpnl87/supermarket,dpnl87/supermarket,nellshamrell/supermarket,leftathome/supermarket,jzohrab/supermarket,chef/supermarket,tas50/supermarket,nellshamrell/supermarket,tas50/supermarket,robbkidd/supermarket,juliandunn/supermarket,chef/supermarket,robbkidd/supermarket,chef/supermarket,leftathome/supermarket,robbkidd/supermarket,tas50/supermarket,rafaelmagu/supermarket,tas50/supermarket,juliandunn/supermarket,dpnl87/supermarket,chef/supermarket,leftathome/supermarket,leftathome/supermarket,jzohrab/supermarket,nellshamrell/supermarket,jzohrab/supermarket,jzohrab/supermarket,rafaelmagu/supermarket,robbkidd/supermarket