title: Can't create conda enviroment having visual studio error
body: <p>I have the following problem:
  Calling </p>
  
  <pre><code>conda env create environment.yml
  </code></pre>
  
  <p>where .yml file contains:</p>
  
  <pre><code>name: my_env
  dependencies:
    - pip:
        - -r file:requirements.txt
  </code></pre>
  
  <p>And I got an error</p>
  
  <pre><code> Microsoft Visual C++ 14.0 is required. Get it with "Build Tools for Visual Studio"
  </code></pre>
  
  <p>For almost every package I need to install.
  VC++ Build tools are definetely installed and every single package from requirements.txt can be installed with either conda install or pip install without any problems whilst they can't be installed with create env as described above.
  What is the problem?</p>