Make purepy a tag on starforge/manylinux1 so that it's not a separate image in docker hub.
Make purepy a tag on starforge/manylinux1 so that it's not a separate
image in docker hub.

galaxyproject/starforge,galaxyproject/starforge,natefoo/starforge,bgruening/docker-build,bgruening/docker-build,natefoo/starforge