Update travis

.travis.yml

@@ -31,8 +31,7 @@ install:
       conda create -q -n test-environment python=$TRAVIS_PYTHON_VERSION
       numpy scipy nose pandas matplotlib mkl-service theano
   - source activate test-environment
-  - pip install https://storage.googleapis.com/tensorflow/linux/cpu/tensorflow-1.8.0-cp34-cp34m-linux_x86_64.whl
-  - pip install pypandoc pylint
+  - pip install tensorflow pypandoc pylint
   - pip install -r requirements.txt
   - pip install .
   - pip install coveralls