Use Codecov instead of coveralls

Author: Sergey Vilgelm

.github/workflows/test.yml

@@ -61,13 +61,8 @@ jobs:
           pip install ".[test]"
       - name: Test with inv
         run: inv cover qa
-      - name: Coveralls
-        if: github.repository == 'python-restx/flask-restx' && github.event == 'push'
-        run: |
-          pip install coveralls
-          coveralls --rcfile=coverage.rc
-        env:
-          COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}
+      - name: Codecov
+        uses: codecov/codecov-action@v1
   bench:
     needs: unit-tests
     runs-on: ubuntu-latest