Fix healthcheck commands (#1151)

ref #1150

the backend healthcheck on localhost doesn't work, needs to be
`0.0.0.0`:

```
/app $ wget --spider http://localhost:8400/ping
Connecting to localhost:8400 ([::1]:8400)
wget: can't connect to remote host: Connection refused
```

Author: evroon

backend/Dockerfile

@@ -18,8 +18,8 @@ RUN set -ex \
 
 EXPOSE 8400
 
-HEALTHCHECK --interval=15s --timeout=5s --retries=5 \
-    CMD wget --spider http://localhost:8400 || exit 1
+HEALTHCHECK --interval=10s --timeout=5s --retries=5 \
+    CMD wget --spider http://0.0.0.0:8400/ping || exit 1
 
 CMD pipenv run gunicorn \
     -k uvicorn.workers.UvicornWorker \

frontend/Dockerfile

@@ -51,7 +51,7 @@ EXPOSE 3000
 
 ENTRYPOINT ["/app/entrypoint.sh"]
 
-HEALTHCHECK --interval=15s --timeout=5s --retries=5 \
+HEALTHCHECK --interval=10s --timeout=5s --retries=5 \
     CMD wget --spider http://localhost:3000 || exit 1
 
 CMD yarn start