Documentation: Add lclarkmichalek/etcdhcp to integrations list

Documentation/integrations.md

@@ -157,3 +157,4 @@
 - [ryandoyle/nss-etcd](https://github.com/ryandoyle/nss-etcd) - A GNU libc NSS module for resolving names from etcd.
 - [Gru](https://github.com/dnaeon/gru) - Orchestration made easy with Go
 - [Vitess](http://vitess.io/) - Vitess is a database clustering system for horizontal scaling of MySQL.
+- [lclarkmichalek/etcdhcp](https://github.com/lclarkmichalek/etcdhcp) - DHCP server that uses etcd for persistence and coordination.