Add automated Fly.io deployments

Signed-off-by: Gunwant Jain <mail@wantguns.dev>

.github/workflows/flyci.yml

@@ -0,0 +1,20 @@
+name: Fly.io Deploy
+
+on:
+  workflow_run:
+    workflows: ["Docker CI"]
+    types: 
+      - completed
+
+env:
+  FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}
+
+jobs:
+  deploy:
+      name: Deploy app
+      runs-on: ubuntu-latest
+      steps:
+        - uses: actions/checkout@v2
+        - uses: superfly/flyctl-actions@1.1
+          with:
+            args: "deploy"