Feature/workflow release (#18)

* Add dry run for twine commands

* Add release workflow

To test it first we let it run in `PYPI_DRY_RUN`.

* fix typo in env var

Author: cmeissner

.github/workflows/release.yml

@@ -23,5 +23,5 @@ jobs:
     - name: Build and publish
       env:
         PYPI_API_TOKEN: ${{ secrets.PYPI_API_TOKEN }}
-        PYPY_DRY_RUN: True
+        PYPI_DRY_RUN: True
       run: make publish