Box bound precision warning generated by gym

[willclarktech]

When using pybullet envs with gym I get the following warning:

~/.venv/lib/python3.6/site-packages/gym/logger.py:30: UserWarning: WARN: Box bound precision lowered by casting to float32
  warnings.warn(colorize('%s: %s'%('WARN', msg % args), 'yellow'))

I'm not sure exactly where this originates because the logger doesn't provide a stacktrace, but for example on this line the dtype is passed as a kwarg:

https://github.com/bulletphysics/bullet3/blob/0ebc43b/examples/pybullet/gym/pybullet_envs/deep_mimic/gym_env/deep_mimic_env.py#L118

I believe if you know you want to lower the precision you're supposed to cast the values yourself, eg:

self.observation_space = spaces.Box(np.float32(observation_min), np.float32(observation_min))