add some coverage config

.coveragerc

@@ -0,0 +1,10 @@
+[report]
+# Regexes for lines to exclude from consideration
+exclude_lines =
+    pragma: no cover
+    def __repr__
+    if self\.debug
+    raise AssertionError
+    raise NotImplementedError
+    if 0:
+    if __name__ == .__main__.:

.github/workflows/pytest.yml

@@ -32,7 +32,7 @@ jobs:
         run: |
           pip install pytest
           pip install pytest-cov
-          pytest --cov=./ --cov-report=xml
+          pytest --cov=./ --cov-report=xml --cov-config=.coveragerc
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v1
         with: