title: RL problem on COLAB for 'gym.envs.box2d' has no attribute 'LunarLander'
body: <p>What can I do in Colab to work with the env &quot;LunarLander-v2&quot; from OPENAI-gym. I have installed <strong>BOX2D</strong> and <strong>box2d-py</strong> but always return the same error:</p>
  <pre><code>AttributeError: module 'gym.envs.box2d' has no attribute 'LunarLander'
  </code></pre>
  <p>This passage in my local machine works, but on Colab not.
  What could be a solution ?</p>
  <p>Versions:
  Python:3.6    -   Gym:0.17.2      -     BOX2D:2.3.10</p>