Add missing dependencies for ray.tune/rllib to wheel

[rshin]

System information

• OS Platform and Distribution (e.g., Linux Ubuntu 16.04): Ubuntu 16.04
• Ray installed from (source or binary): binary
• Ray version: 0.3.0
• Python version: 2.7.12
• Exact command to reproduce: Create a new virtualenv, install ray with pip, then import ray.tune.

Describe the problem

ray.tune depends on, through rllib:

• OpenAI Gym (gym)
• OpenCV (cv2)
• scipy

but they are not specified as dependencies of the wheel on PyPI.

[richardliaw]

It would be nice to see rllib (and its dependencies) separated from tune. The current problem is that ScriptRunner in tune inherits from Agent which is a RLlib class.

Agent is RL specific because of three things:

1. environment support (L92 to 102)
2. compute_action
3. Logging

Other things in Agent are nice to haves that seem to be applicable for generic functions. One option would be to duplicate code from Agent to ScriptRunner. Other option would be to introduce a layer beneath Agent and above Trainable that offers the non-RL specific functionality of Agent.

[richardliaw]

Also related #1364 and #1144 (along others). tl;dr Tune should not depend on RLlib

@ericl thoughts on post above?

[richardliaw]

Fixed in #1454!