make provider a string so it can be parsed for '@'

Signed-off-by: Steve Loranz <sloranz@redhat.com>
set the builder's provider_image to the passed in image_object

Signed-off-by: Steve Loranz <sloranz@redhat.com>
set the active image so activity doesn't break

Signed-off-by: Steve Loranz <sloranz@redhat.com>
read the credential file contents instead of passing the file

Signed-off-by: Steve Loranz <sloranz@redhat.com>
fixes to delete_from_provider

Signed-off-by: Steve Loranz <sloranz@redhat.com>
Merge pull request #285 from aeolusproject/bug/fix-provider-img-deletion

Fixed deletion of provider images