Add Health Check endpoint (#392)

* add simple health endpoint

* add curl and healthcheck to dockerfile

* convert to view

* add simple test

* Add unhealthy test

* Cleanup

* check for LD_SERVER_PORT env var in healthcheck def

* Revert changes to middlewares.py

Co-authored-by: Sascha Ißbrücker <sascha.issbruecker@gmail.com>

bookmarks/views/__init__.py

@@ -1,3 +1,4 @@
 from .bookmarks import *
 from .settings import *
 from .toasts import *
+from .health import health