message: Pin psutils to previous version because latest one fails to install for Python 2.7.
  The error is `egg_base must be a directory name`.
diff: @@ -87,8 +87,9 @@ pip2 install pandas==0.19.2
  pip3 install pandas==0.19.2
  # Benchmark tests require the following:
  -pip2 install psutil
  -pip3 install psutil
  +# 5.6.4 fails to pip2 install. TODO(b/143872855): remove pinning once fixed.
  +pip2 install psutil==5.6.3
  +pip3 install psutil==5.6.3
  pip2 install py-cpuinfo
  pip3 install py-cpuinfo
  