message: Fix for horovod tests. Change the way tf-nightly is installed.
diff: # limitations under the License.
  # ==============================================================================
  set -e
  +set -x
  # TODO(pkanwar): upgrade to 3.7.
  PIP_CMD="pip3.5"
  @@ -25,15 +26,11 @@ source tensorflow/tools/ci_build/release/common.sh
  install_bazelisk
  which bazel
  -# Install pip3.5
  -curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
  -sudo python3.5 get-pip.py
  -
  # Install realpath
  sudo apt-get install realpath
  # Install tf-nightly and verify version.
  -"${PIP_CMD}" install --user tf-nightly
  +python3.5 -m "${PIP_CMD}" install --user tf-nightly
  python3.5 -c "import tensorflow as tf; print(tf.__version__)"
  @@ -56,7 +53,8 @@ sudo ldconfig
  # Install Horovod.
  cd ..
  -"${PIP_CMD}" install horovod tensorflow
  +HOROVOD_WITH_TENSORFLOW=1
  +"${PIP_CMD}" install horovod[tensorflow]
  # Install tests.
  git clone https://github.com/DEKHTIARJonathan/TF_HVD_Stability_Test.git
  