DCOS-40885 Re-add pip dependencies required by external repos (#2635)
DCOS-40885 Re-add pip dependencies required by external repos (#2635)

These can be removed someday after external repos (spark-build, dcos-zookeeper, ...) no longer depend on them.
mesosphere/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons