* python_test: fix cython_examples in doc/ and tests/
* update setup.py to parse the bazel version string better
* all: centralize all python deps into stackable requirements files in python/
* format
* Move cython test into the proper package
* Add cross-reference dependency comments for requirements and setup.py
* re-enable version pinning on CI, fix formatting
* fix up torchvision version
* fix case in shell
* Remove all __future__ imports from RLlib.
* Remove (object) again from tf_run_builder.py::TFRunBuilder.
* Fix 2xLINT warnings.
* Fix broken appo_policy import (must be appo_tf_policy)
* Remove future imports from all other ray files (not just RLlib).
* Remove future imports from all other ray files (not just RLlib).
* Remove future import blocks that contain `unicode_literals` as well.
Revert appo_tf_policy.py to appo_policy.py (belongs to another PR).
* Add two empty lines before Schedule class.
* Put back __future__ imports into determine_tests_to_run.py. Fails otherwise on a py2/print related error.
