Merge branch 'feature/continuous-integration' into 'master'

Continuous Integration Updates

- Add `.travis.yml` for GitHub (first set of tests were run [here](https://travis-ci.org/PyCQA/flake8/builds/44403113))

- Update `tox.ini` to add

 - `py25` environment

 - `py{27,34}-flake8` environments

See merge request !12 (https://gitlab.com/pycqa/flake8/merge_requests/12)

.travis.yml

@@ -0,0 +1,20 @@
+language: python
+before_script:
+- pip install tox
+
+# test script
+script:  tox -e ${TOX_ENV}
+notifications:
+  on_success: change
+  on_failure: always
+
+env:
+  matrix:
+  - TOX_ENV=py26
+  - TOX_ENV=py27
+  - TOX_ENV=py32
+  - TOX_ENV=py33
+  - TOX_ENV=py34
+  - TOX_ENV=pypy
+  - TOX_ENV=py27-flake8
+  - TOX_ENV=py34-flake8

tox.ini

@@ -1,7 +1,7 @@
 [tox]
 minversion = 1.6
 envlist =
-    py26,py27,py32,py33,py34
+    py25,py26,py27,py32,py33,py34,py27-flake8,py34-flake8
 
 [testenv]
 usedevelop = True
@@ -10,6 +10,18 @@ commands =
     python setup.py test -q
     python setup.py flake8
 
+[testenv:py27-flake8]
+basepython = python2.7
+deps =
+    flake8
+commands = flake8 {posargs} flake8/
+
+[testenv:py34-flake8]
+basepython = python3.4
+deps =
+    flake8
+commands = flake8 {posargs} flake8/
+
 [flake8]
 select = E,F,W
 max_line_length = 79