update runner to run unit tests more like portage

Signed-off-by: Zen <[email protected]>

Author: desultory

.github/workflows/unit_tests.yml

@@ -31,5 +31,4 @@ jobs:
         venv/bin/pip install .
     - name: Run unit tests
       run: |
-        cd tests
-        ../venv/bin/python -m unittest -v
+        venv/bin/python -m unittest -v discover tests