title: Can't see python libs inside Docker image
body: <p>I want to build Docker container with python 3.6 and few dependencies.
  Here is my Dockerfile:</p>
  
  <pre><code>FROM noondotcom/alpine-3.6-python-3.6-grpc
  
  COPY requirements.txt /requirements.txt
  RUN python3.6 -m pip install --upgrade pip
  RUN python3.6 -m pip install -r requirements.txt
  CMD ["python3.6", "-m requests"]
  </code></pre>
  
  <p><strong>docker build -f Dockerfile .</strong> executed without errors and I see all libs in <em>requirements.txt</em> are installed</p>
  
  <p>But when I run <strong>docker run</strong> I got "No module named requests" message.</p>
  
  <p>How I can fix that?</p>