Monitor LDAP sync

In GHE you can define the [LDAP sync intervals](https://help.github.com/enterprise/2.12/admin/guides/user-management/using-ldap/#enabling-ldap-sync). The sync time should always be smaller than the sync interval. You can monitor the sync time (for ldap team syncs) of your GHE appliance as follows:
```
$ zcat -f production.log* | perl -ne 'print if s/^(.*) \+.*resque\.performed.*ldap_team_sync.*?([0-9\.]+ms)$/\1 \2/' | sort
```

The issue names production.log* and provides a zcat, Perl, and sort command for LDAP team-sync timings on a GHE appliance. Start by clarifying whether Hubble should collect, display, or alert on this metric; completion criteria and a repository entry point are not specified.

Written by the indexing model from the issue text.