Convert code to python 2.7 (#35)

* Convert code format to python2.7 (SAC)

* Convert code format python2.7 (TD3, all fD)

* Remove no use import and black setting

* Change SAC param

* Change env name Reacher-v2 to v1

* Remove old version reacher training script

* Convert code format python2.7

* Modify .travis.yml

* Add install command python3.6 & black on Makefile

* Fix seperator to tab on Makefile

* Modify Makefile

* Fix little error

* Change td3 gamma parameter

scripts/requirements-dev.txt

@@ -1,14 +1,12 @@
 pre-commit
 
 # formatting
-black
 isort
+# black -> in Makefile
 
 # testing
-flake8==3.6.0
-flake8-bugbear
-flake8-docstrings
-pytest>=4.0.0
+flake8
+pytest
 pytest-flake8
 pytest-cov