Use Coveralls action and remove redundant coverage install from jython setup file

.github/workflows/python-package.yml

@@ -44,5 +44,7 @@ jobs:
     - name: Test with tox for non Jython only
       if: ${{ ! matrix.jython }}
       run: tox
-    - name: Run coveralls
-      run: coveralls
+    - name: Coveralls
+      uses: coverallsapp/github-action@master
+      with:
+        github-token: ${{ secrets.GITHUB_TOKEN }}