Do not git clone two times

docker/tensorflow/Dockerfile

@@ -44,8 +44,8 @@ RUN apt-get update && sudo apt-get install -y --force-yes --no-install-recommend
 RUN apt-get upgrade -y --force-yes --no-install-recommends bazel
 
 # CLONE FROM GIT
-RUN git clone https://github.com/tensorflow/tensorflow
-WORKDIR /tensorflow
+#RUN git clone https://github.com/tensorflow/tensorflow
+#WORKDIR /tensorflow
 
 ##################################################
 # Make sure important packages are installed
@@ -75,8 +75,8 @@ RUN mkdir /bazel && \
 # Download and build TensorFlow.
 
 RUN git clone https://github.com/tensorflow/tensorflow.git && \
-    cd tensorflow && \
-    git checkout r1.2
+    cd tensorflow
+#    git checkout r1.2
 WORKDIR /tensorflow
 
 # TODO(craigcitro): Don't install the pip package, since it makes it