box2d kengz vs py (openai#1120)

* try build with box2d-kengz

* test box2d envs

* use box2d-py in tox.ini for tests

* box2d-py instead of box2d-kengz in box2d dependencies

* test dependencies in tox.ini use dependencies in setup.py

* further cleanups of tox.ini

* further cleanups

* added scipy to list of requirements

* added a note about box2d-kengz into README

* build box2d from scratch, add a note to README about it

* use box2d-py>=2.3.4

* removed box2d installation instructions from README

setup.py

@@ -8,7 +8,7 @@
 # Environment-specific dependencies.
 extras = {
   'atari': ['atari_py>=0.1.1', 'Pillow', 'PyOpenGL'],
-  'box2d': ['box2d-py'],
+  'box2d': ['box2d-py>=2.3.4'],
   'classic_control': ['PyOpenGL'],
   'mujoco': ['mujoco_py>=1.50', 'imageio'],
   'robotics': ['mujoco_py>=1.50', 'imageio'],

tox.ini

@@ -16,12 +16,3 @@ deps =
 commands =
     pytest {posargs}
 
-[testenv:py27]
-whitelist_externals=make
-passenv=DISPLAY TRAVIS*
-deps =
-    pytest
-    mock
-    -e .[all]
-commands =
-    pytest {posargs}