Allow submission of checkin information via json
Allow submission of checkin information via json

This means we still allow pickle submissions as a stopgap until we
manage to convince admins to move to json submissions.

Related: CVE-2016-1000003
Signed-off-by: Patrick Uiterwijk <bd6d5394796bee9cca2245486eb583fd64b70226@redhat.com>

pombredanne/mirrormanager2,pombredanne/mirrormanager2,pombredanne/mirrormanager2,pombredanne/mirrormanager2