Cppyythonizations

**Changed:**

* use GitHub Actions for CI

**Fixed:**

* fixed errors in doctests for tuple and vector pythonizations

**Added:**

* workaround for printing and indexing into tuples, see https://bitbucket.org/wlav/cppyy/issues/272/pythonization-on-tuple-erases-__getitem__

**Fixed:**

* typo in rever deployment script

so that conda-smithy sees a commit tag in this repository