refined requirements for virtual env

requirements.txt

-Keras>=2.0.8
-# mlpy 3.5.0
-git+https://gitlab.fbk.eu/MPBA/mlpy.git
-numpy>=1.12
-pandas>=0.20.0
-scikit-learn>=0.19
-scipy>=0.19
-tensorflow
+absl-py==0.2.2
+astor==0.6.2
+bleach==1.5.0
+gast==0.2.0
+grpcio==1.12.1
+h5py==2.8.0
+html5lib==0.9999999
+Keras==2.1.6
+Markdown==2.6.11
+numpy==1.14.3
+pandas==0.23.0
+pip==10.0.1
+protobuf==3.5.2.post1
+python-dateutil==2.7.3
+pytz==2018.4
+PyYAML==3.12
+scikit-learn==0.19.1
+scipy==1.1.0
+six==1.11.0
+tensorboard==1.8.0
+tensorflow-gpu==1.8.0
+termcolor==1.1.0
+Werkzeug==0.14.1