title: openai gym box space configuration
body: <p>I need an observation space ranging from [0,inf)<br>
  I'm new to openai gym, and not sure what the format should be</p>
  
  <pre><code>from gym spaces
  
  spaces.Box(np.array(0),np.array(np.inf))
  # Box()
  
  spaces.Box(0, np.inf, shape = (1,))
  # Box(1,)
  </code></pre>