Update to libmodulemd 0.2.0
    
    Adds gtk-doc generated documentation
    (ABI-break) Makes all optional properties accept NULL as a value to clear
      them
    (ABI-break) Modulemd.SimpleSet takes a STRV (char **) instead of a
      GLib.PtrArray
    Fixes a bug where the name was not always set for components
    Adds support for dumping YAML from the introspected API
    Includes add/remove routines for profiles
    
    Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>