🔖 cd: publish prerelease (#57)

.github/workflows/cd.yml

@@ -0,0 +1,23 @@
+name: CD
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  prerelease:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 100
+      - name: Pre-release (.devN)
+        run: |
+          git fetch --depth=1 origin +refs/tags/*:refs/tags/*
+          pip install twine wheel
+          ./scripts/release.sh
+        env:
+          TWINE_USERNAME: ${{ secrets.TWINE_USERNAME }}
+          TWINE_PASSWORD: ${{ secrets.TWINE_PASSWORD }}
+          JINA_SLACK_WEBHOOK: ${{ secrets.JINA_SLACK_WEBHOOK }}