[BRING BACK TO MASTER] Fix cluster.yaml config.

ci/microbenchmark/ray-project/cluster.yaml

@@ -44,6 +44,7 @@ head_setup_commands:
     - wget --quiet https://repo.continuum.io/archive/Anaconda3-5.0.1-Linux-x86_64.sh || true
     - bash Anaconda3-5.0.1-Linux-x86_64.sh -b -p $HOME/anaconda3 || true
     - echo 'export PATH="$HOME/anaconda3/bin:$PATH"' >> ~/.bashrc
+    - pip install -U pip 
 
 # Custom commands that will be run on worker nodes after common setup.
 worker_setup_commands: []

ci/regression_test/stress_tests/ray-project/cluster.yaml

@@ -96,6 +96,7 @@ setup_commands:
     # # Build Ray.
     # - git clone https://github.com/ray-project/ray || true
     # - ray/ci/travis/install-bazel.sh
+    - pip install -U pip 
     - pip install boto3==1.4.8 cython==0.29.0
     # - cd ray/python; git checkout master; git pull; pip install -e . --verbose
     - "pip install https://s3-us-west-2.amazonaws.com/ray-wheels/{{ray_branch}}/{{commit}}/ray-{{ray_version}}-cp36-cp36m-manylinux1_x86_64.whl"