PEP-8 Fixes in algorithmic environment (#1382)

Remove trailing whitespaces.
Make line breaks adhere to 80 character limit (not all, but quite a few).
Remove unused imports.
Other miscellaneous PEP-8 fixes.

gym/envs/algorithmic/duplicated_input.py

@@ -5,6 +5,7 @@ http://arxiv.org/abs/1511.07275
 from __future__ import division
 from gym.envs.algorithmic import algorithmic_env
 
+
 class DuplicatedInputEnv(algorithmic_env.TapeAlgorithmicEnv):
     def __init__(self, duplication=2, base=5):
         self.duplication = duplication