We had this error in our neo4j pod recently:
```
2019-12-02 08:29:42.680+0000 ERROR Unable to schedule bolt session 'bolt-1018230' for execution since there are no available threads to serve it at the moment. You can retry at a later time or consider increasing max thread pool size for bolt connector(s).
2019-12-02 08:29:42.680+0000 ERROR Unable to schedule bolt session 'bolt-1018224' for execution since there are no available threads to serve it at the moment. You can retry at a later time or consider increasing max thread pool size for bolt connector(s).
2019-12-02 08:29:42.681+0000 ERROR Unable to schedule bolt session 'bolt-1018352' for execution since there are no available threads to serve it at the moment. You can retry at a later time or consider increasing max thread pool size for bolt connector(s).
2019-12-02 08:29:42.682+0000 ERROR Unable to schedule bolt session 'bolt-1018243' for execution since there are no available threads to serve it at the moment. You can retry at a later time or consider increasing max thread pool size for bolt connector(s).
```
Apparently the default is 400 threads. So we must have a leak somewhere.
* If the email middleware does not send mails, it will give a warning
similar to sentry middleware
* Eliminated GrapphQLClient in one more test
* Rename code => nonce
This commit takes all backend changes for signup and invite feature. I
was working on these features and removed the generated mutations for
type user along the way.
Credit: https://github.com/wildbit/postmark-templates/
Also we distinguish now if a user has been found and if not. The
password reset link brings us directly to the last step in the flow.
.. but enable it by default for `docker-compose.override.yml`. If the developer
uses `docker-compose` we can safely assume that a local smtp server for
development is running.
