title: use pipenv for running unittest on jenkins takes too long
body: <p>We migrated to from pip to pipenv. </p>
  
  <p>I think pipenv is great, but ran into a problem. </p>
  
  <p>We run our unittests on every push using git webhook to jenkins. When Using pip, we had a virtual environment and we would activate it and install our requiremnets.txt file before running the tests. </p>
  
  <p>This was pretty fast, pip would run throught the requiremnets that were already met and only install a dependency when one was added.</p>
  
  <p>With Pipenv, I have the Pipfile and the Pipfile.lock in the root of the repo, and running <code>pipenv install</code> seems like its recreating the environment every time, and takes a very long time.</p>
  
  <p>This could be a read deal breaker for us.</p>
  
  <p>Is there any workaroud so I can speed up working with pipenv?</p>
  
  <p>Previous shell script (in the jenkins job) was something like:</p>
  
  <pre><code>eval "$(pyenv init -)"
  eval "$(pyenv virtualenv-init -)"
  pyenv activate romee
  
  pip install -r requirements.txt
  pip install -r requirements-dev.txt
  
  python tests.py
  </code></pre>
  
  <p>With pipenv:</p>
  
  <pre><code>pipenv install
  pipenv install --dev
  pipenv run python run_tests.py
  </code></pre>