Adding flask and heartbeat

src/app.py

@@ -0,0 +1,21 @@
+from flask import Flask, jsonify
+from datetime import datetime, timezone
+
+app = Flask(__name__)
+
+
+@app.get("/heartbeat")
+def heartbeat() -> tuple:
+    return (
+        jsonify(
+            {
+                "status": "ok",
+                "timestamp": datetime.now(timezone.utc).isoformat(),
+            }
+        ),
+        200,
+    )
+
+
+if __name__ == "__main__":
+    app.run(debug=True)