Add deploy step and remove appveyor

Author: DanielBok

.appveyor.yml

@@ -135,3 +135,36 @@ jobs:
 
           pip install ${file}
           python extern/nlopt/test/t_python.py
+
+  deploy:
+    name: deploy packages
+    runs-on: ubuntu-latest
+    needs: test-wheels
+    if: startsWith(github.ref, 'refs/tags/')
+
+    steps:
+      - name: Setup Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Retrieve packages
+        uses: actions/download-artifact@v2
+        with:
+          name: artifact
+          path: dist
+
+      - name: Install twine
+        run: pip install twine
+
+      - name: Upload packages to testpypi
+        env:
+          TWINE_USERNAME: ${{ secrets.PYPI_TEST_UID }}
+          TWINE_PASSWORD: ${{ secrets.PYPI_TEST_PWD }}
+        run: python -m twine upload --skip-existing --repository testpypi dist/*
+
+      - name: Upload packages to pypi
+        env:
+          TWINE_USERNAME: ${{ secrets.PYPI_UID }}
+          TWINE_PASSWORD: ${{ secrets.PYPI_PWD }}
+        run: python -m twine upload --skip-existing dist/*