pybulllet environments don't visualize

[d9w]

This may be an issue in PyCall.jl. Normally env[:render] returns true and displays the environment (for example, for env = gym.make("CartPole-v0"), but for pybullet envs this doesn't work:

julia> env[:render](mode="human")
0-element Array{Float64,1}

[d9w]

Calling env[:reset] before calling env[:render] for the first time will make this happen on pybullet envs, and creating a new env for rendering errors.

Running a new environment with env[:render] works, but is very slow. Something about calling pybullet env's render method from PyCall.jl introduces a large delay.

[d9w]

scripts/gym.jl now visualizes pybullet envs