Add release pipeline (#12)

* add release pipeline

.github/workflows/release.yaml

@@ -0,0 +1,93 @@
+name: Release to latest/edge
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  lib-check:
+    name: Check libraries
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Check libs
+        uses: canonical/charming-actions/[email protected]
+        with:
+          credentials: "${{ secrets.CHARMHUB_TOKEN }}" # FIXME: current token will expire in 2023-07-04
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install dependencies
+        run: python3 -m pip install tox
+      - name: Run linters
+        run: tox -e lint
+
+  unit-test:
+    name: Unit tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install dependencies
+        run: python -m pip install tox
+      - name: Run tests
+        run: tox -e unit
+
+  security-test:
+    name: Security tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Install dependencies
+        run: python -m pip install tox
+      - name: Run tests
+        run: tox -e security
+
+  integration-test:
+    name: Integration tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Setup operator environment
+        uses: charmed-kubernetes/actions-operator@main
+        with:
+          provider: microk8s
+          # This is needed until https://bugs.launchpad.net/juju/+bug/1977582 is fixed
+          bootstrap-options: "--agent-version 2.9.29"
+      - name: Run integration tests
+        run: tox -e integration
+
+  release-to-charmhub:
+    name: Release to CharmHub
+    needs:
+      - lib-check
+      - lint
+      - unit-test
+      - security-test
+      - integration-test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Select charmhub channel
+        uses: canonical/charming-actions/[email protected]
+        id: channel
+      - name: Upload charm to charmhub
+        uses: canonical/charming-actions/[email protected]
+        with:
+          credentials: "${{ secrets.CHARMHUB_TOKEN }}"
+          github-token: "${{ secrets.GITHUB_TOKEN }}"
+          channel: "${{ steps.channel.outputs.name }}"