title: Circular dependency when installing numpy
body: <p>I am trying to install numpy in my virtualenv but I face circular dependencies as follow:</p>
  
  <pre><code>(test) [hadoop@ip-192-168-26-8 test]$ python -m pip install numpy
  Collecting numpy
    Using cached https://files.pythonhosted.org/packages/62/20/4d43e141b5bc426ba38274933ef8e76e85c7adea2c321ecf9ebf7421cedf/numpy-1.18.1-cp36-cp36m-manylinux1_x86_64.whl
  ERROR: tensorboard 2.1.0 requires grpcio&gt;=1.24.3, which is not installed.
  ERROR: tensorboard 2.1.0 requires markdown&gt;=2.6.8, which is not installed.
  ERROR: tensorboard 2.1.0 requires protobuf&gt;=3.6.0, which is not installed.
  ERROR: tensorboard 2.1.0 requires werkzeug&gt;=0.11.15, which is not installed.
  Installing collected packages: numpy
  Successfully installed numpy-1.18.1
  </code></pre>
  
  <p>then when I try to install grpcio</p>
  
  <pre><code>(test) [hadoop@ip-192-168-26-8 test]$ python -m pip install grpcio
  Collecting grpcio
    Using cached https://files.pythonhosted.org/packages/17/8f/f79c5c174bebece41f824dd7b1ba98da45dc2d4c373b38ac6a7f6a5acb5e/grpcio-1.26.0-cp36-cp36m-manylinux2010_x86_64.whl
  Requirement already satisfied: six&gt;=1.5.2 in ./lib/python3.6/dist-packages (from grpcio) (1.14.0)
  ERROR: tensorboard 2.1.0 requires markdown&gt;=2.6.8, which is not installed.
  ERROR: tensorboard 2.1.0 requires numpy&gt;=1.12.0, which is not installed.
  ERROR: tensorboard 2.1.0 requires protobuf&gt;=3.6.0, which is not installed.
  ERROR: tensorboard 2.1.0 requires werkzeug&gt;=0.11.15, which is not installed.
  Installing collected packages: grpcio
  Successfully installed grpcio-1.26.0
  </code></pre>
  
  <p>I am not even sure why it gives me incorrect prompt <code>Successfully installed grpcio-1.26.0</code>, as they are not being added to my pip when I use list command.</p>