RPM Support

Add a MongoEngine model to represent the Modulemd content type.

Modulemd model :

Name - string
Stream - string
Version - integer
Context - string
Arch - string
Summary - string
Description - string
Profiles - dict ( key - profile name, value - list of rpms)
Servicelvels - dict
Artifacts - list or rpm - list
_storage_path --> yaml stored on the disk - string
checksum ( for yaml integrity check) - string
checksumtype - string

The unit_key is NSVCA.

• To parse module.yaml doc we'll use Modulemd.objects_from_file() from libmodulemd
• To Write module out to a YAML document on disk we'll use Modulemd.Module.dump () from libmodulemd.
• Spec of the Modulemd for reference https://github.com/fedora-modularity/libmodulemd/blob/master/spec.v2.yaml
• library for the reference https://sgallagh.fedorapeople.org/docs/libmodulemd/1.4/