Set logger name

`logger` is a required field (although a default is specified).
<http://sentry.readthedocs.org/en/latest/developer/client/index.html#bui
lding-the-json-packet>

If you want to use a Writer with the log pkg, you can specify the
logger name there too.

Update client-test for required logger field

Change LoggerName to Logger to match Packet field

Sloppy!

Maybe I'm serious about tests this time