Fix Gym and NumPy versions and environment names in README

[lcdbezerra]

I noticed the package is not compatible with recent NumPy and Gym versions, so I set them to numpy==1.26.1 and gym==0.23.1 in setup.py. This seemed to fix the compatibility issues. In addition, I fixed the environment names in README.md.

ISSUES:

>>> env = gym.make("maze-sample-3x3")
>>> obs = env.reset()
>>> act = env.action_space.sample()
>>> obs = env.step(act)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/USERNAME/miniconda3/envs/gymtest/lib/python3.10/site-packages/gym-0.26.2-py3.10.egg/gym/wrappers/time_limit.py", line 50, in step
    observation, reward, terminated, truncated, info = self.env.step(action)
  File "/Users/USERNAME/miniconda3/envs/gymtest/lib/python3.10/site-packages/gym-0.26.2-py3.10.egg/gym/wrappers/order_enforcing.py", line 37, in step
    return self.env.step(action)
  File "/Users/USERNAME/miniconda3/envs/gymtest/lib/python3.10/site-packages/gym-0.26.2-py3.10.egg/gym/wrappers/env_checker.py", line 37, in step
    return env_step_passive_checker(self.env, action)
  File "/Users/USERNAME/miniconda3/envs/gymtest/lib/python3.10/site-packages/gym-0.26.2-py3.10.egg/gym/utils/passive_env_checker.py", line 225, in env_step_passive_checker
    if not isinstance(done, (bool, np.bool8)):
  File "/Users/USERNAME/miniconda3/envs/gymtest/lib/python3.10/site-packages/numpy-2.1.2-py3.10-macosx-10.15-x86_64.egg/numpy/__init__.py", line 414, in __getattr__
    raise AttributeError("module {!r} has no attribute "
AttributeError: module 'numpy' has no attribute 'bool8'. Did you mean: 'bool'?

>>> env = gym.make("maze-sample-3x3")
>>> obs = env.reset()
>>> act = env.action_space.sample()
>>> obs = env.step(act)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/USERNAME/miniconda3/envs/gymtest/lib/python3.10/site-packages/gym-0.26.2-py3.10.egg/gym/wrappers/time_limit.py", line 50, in step
    observation, reward, terminated, truncated, info = self.env.step(action)
ValueError: not enough values to unpack (expected 5, got 4)