[CCI] Adding init coverage for PackageSubscriber, PackagePushError, PackagePushJob, and PackagePushRequest. Also testing version_number property for MetadataPackage class.
[CCI] Adding init coverage for PackageSubscriber, PackagePushError, PackagePushJob, and PackagePushRequest. Also testing version_number property for MetadataPackage class.

SalesforceFoundation/CumulusCI,SalesforceFoundation/CumulusCI