Load hipchat into riemann namespace

Fixes:
```
INFO [2013-12-10 17:36:26,647] main - riemann.bin - PID 81295

ERROR [2013-12-10 17:36:26,674] main - riemann.bin - Couldn't start java.lang.RuntimeException: Unable to resolve symbol: hipchat in this context, compiling:(etc/riemann.config:6:9)
```
Merge pull request #291 from digital-science/add_hipchat_to_config

Load hipchat into riemann namespace