[PATCH] Add configurable compression type to mash (default to xz)

[Bill Nottingham]

Ralph Bean (rbean at redhat.com) said: 
> This is for https://fedorahosted.org/rel-eng/ticket/5362#comment:17

...
> diff --git a/mash/metadata.py b/mash/metadata.py
> index 3158086..b3e33ed 100644
> --- a/mash/metadata.py
> +++ b/mash/metadata.py
> @@ -59,6 +59,10 @@ class MetadataOld:
>      def set_database(self, db):
>          self.args.append('-d')
>  
> +    def set_compress_type(self, compress_type):
> +        self.args.append('--compress-type')
> +        self.args.append(compress_type
> +
>      def set_hash(self, hashtype):
>          # Sorry, can't do that here.
>          pass

If we're on a system where createrepo is an old enough release that it can't
be imported, is it still a version that would take this argument?

Otherwise, looks ok.

Bill