Convert to pyproject-rpm-macros, rename the installable package to "tox"

Remove old obsoletes.
Pathlib2 is now only imported on old Pythons.

tests/tests.yml

@@ -24,9 +24,9 @@
     - repo: "https://src.fedoraproject.org/rpms/pyproject-rpm-macros.git"
       dest: "pyproject-rpm-macros"
     tests:
-    - rpmbuild:
+    - mock_with_tests:
         dir: .
-        run: "dnf -y build-dep --define '_with_tests 1' {{ tenv_workdir }}/python-tox.spec && rpmbuild --define '_sourcedir {{ tenv_workdir }}' --with tests -ba {{ tenv_workdir }}/python-tox.spec"
+        run: pyproject-rpm-macros/tests/mocktest.sh python-tox --enable-network --with tests
     - smoke27:
         dir: python/smoke
         run: VERSION=2.7 METHOD=virtualenv ./venv.sh