message: Fix the docker reference to ci.tensorflow.org to now use tf-nightly pip
  packages instead.
diff: @@ -87,8 +87,10 @@ export TF_DOCKER_BUILD_IS_DEVEL=NO
  export TF_DOCKER_BUILD_TYPE=CPU
  export TF_DOCKER_BUILD_PYTHON_VERSION=PYTHON2
  -export NIGHTLY_VERSION="1.head"
  -export TF_DOCKER_BUILD_CENTRAL_PIP=$(echo ${TF_DOCKER_BUILD_PYTHON_VERSION} | sed s^PYTHON2^http://ci.tensorflow.org/view/Nightly/job/nightly-matrix-cpu/TF_BUILD_IS_OPT=OPT,TF_BUILD_IS_PIP=PIP,TF_BUILD_PYTHON_VERSION=${TF_DOCKER_BUILD_PYTHON_VERSION},label=cpu-slave/lastSuccessfulBuild/artifact/pip_test/whl/tensorflow-${NIGHTLY_VERSION}-cp27-cp27mu-manylinux1_x86_64.whl^ | sed s^PYTHON3^http://ci.tensorflow.org/view/Nightly/job/nightly-python35-linux-cpu/lastSuccessfulBuild/artifact/pip_test/whl/tensorflow-${NIGHTLY_VERSION}-cp35-cp35m-manylinux1_x86_64.whl^)
  +pip download --no-deps tf-nightly
  +
  +export TF_DOCKER_BUILD_CENTRAL_PIP=$(ls tf_nightly*.whl)
  +export TF_DOCKER_BUILD_CENTRAL_PIP_IS_LOCAL=1
  tensorflow/tools/docker/parameterized_docker_build.sh
  ```
  