Packages installing python3 site packages for python3 in version 3.x.y
depend on python3~3.x. This automatically adds the required
dependencies.
Unit test cases have been added by reusing the `py3-foo-and-bar` test
package. However, the path of that has been renamed to contain spaces
to be extra sure the logic is safe in regrade to spaces in path
names.
Marian Buschsieweke