Ignore calls to Bugsnag.notify() with no arguments
Ignore calls to Bugsnag.notify() with no arguments

fixes #196

Omniroot/bugsnag-js,Omniroot/bugsnag-js,jacobmarshall/bugsnag-js,jacobmarshall-etc/bugsnag-js,jacobmarshall-etc/bugsnag-js,jacobmarshall/bugsnag-js