project: Switch to Travis CI

Add Travis CI configuration, replace Circle CI build badge with Travis
CI build badge.

.travis.yml

@@ -0,0 +1,15 @@
+language: python
+install: pip install tox coveralls
+matrix:
+  fast_finish: true
+  include:
+    - python: 3.5
+      env: TOXENV=flake8
+    - python: 3.5
+      env: TOXENV=pylint
+    - python: 2.7
+      env: TOXENV=py27
+    - python: 3.5
+      env: TOXENV=py35
+script: tox
+after_success: coveralls

README.rst

@@ -1,6 +1,6 @@
-.. image:: https://circleci.com/gh/fetzerch/fritzcollectd.svg?style=shield
-    :target: https://circleci.com/gh/fetzerch/fritzcollectd
-    :alt: Circle CI Status
+.. image:: https://travis-ci.org/fetzerch/fritzcollectd.svg?branch=master
+    :target: https://travis-ci.org/fetzerch/fritzcollectd
+    :alt: Travis CI Status
 
 .. image:: https://coveralls.io/repos/github/fetzerch/fritzcollectd/badge.svg?branch=master
     :target: https://coveralls.io/github/fetzerch/fritzcollectd?branch=master