Upgrade pants with fixed setup_py command

Upgrade to a new version of pants, which includes the fix for setup_py- AURORA-536

This was built at
https://github.com/pantsbuild/pants/commit/dccd515fb684421f4122df6ff425bfd07359606f
of pants

Testing Done:
$ ./pants ./src/test/python:all

Bugs closed: AURORA-536

Reviewed at https://reviews.apache.org/r/22795/