title: Gitlab CI automatic increase of version of python package
body: <p>We develop a Python package and use gitlab as repository. So far, we increased the version of package (in the <code>__init__.py</code>) manually with every commit on the master branch, i.e. after each successful merged Merge Request or a small bug fix. But often we missed to increase the version string. </p>
  
  <p>However, now we are trying to setup a Gitlab CI/CD pipeline to do the job for us, i.e. to increase the version number in the <code>__init__.py</code> and automatically build and deploy the package to a repository by the pipelines. </p>
  
  <p>However, simply increasing the string during the build is not sufficient since the new string is not committed back to the repo. Can someone give  some hints?</p>