Add flake8 to tox, disable qa on pyHS100/__init__.py, fix py27 compatibility (#31)

pyHS100/__init__.py

@@ -1,3 +1,4 @@
+# flake8: noqa
 from __future__ import absolute_import
 from __future__ import unicode_literals
 from pyHS100.pyHS100 import SmartBulb, SmartPlug, TPLinkSmartHomeProtocol, SmartPlugException

pyHS100/pyHS100.py

@@ -17,6 +17,7 @@ http://www.apache.org/licenses/LICENSE-2.0
 # python2 compatibility
 from __future__ import absolute_import
 from __future__ import unicode_literals
+from future.utils import raise_from
 try:
     basestring
 except NameError:
@@ -70,7 +71,7 @@ class SmartDevice(object):
                 request={target: {cmd: arg}}
             )
         except Exception as ex:
-            raise SmartPlugException(ex) from ex
+            raise_from(SmartPlugException(), ex)
 
         if target not in response:
             raise SmartPlugException("No required {} in response: {}".format(target, response))

tox.ini

@@ -1,13 +1,22 @@
 [tox]
-envlist=py27,py34,py35
+envlist=py27,py34,py35,py36,flake8
 
 [tox:travis]
 2.7 = py27
 3.4 = py34
 3.5 = py35
+3.6 = py36
+
 [testenv]
 deps=
   future
   pytest
   voluptuous
-commands=py.test
+commands=py.test pyHS100
+
+[testenv:flake8]
+deps=flake8
+commands=flake8 pyHS100
+
+[flake8]
+exclude = .git,.tox,__pycache__,pyHS100/tests/fakes.py