Logging chokes on null

[mryellow]

Sending null to be logged results in eventer crashes when emit is attempted. agents.log(null)

agents/index.js

Lines 441 to 445 in 4edc2c7

	Object.assign(context, {
	log: (...msg) => agents.emit('log', session, ...msg),
	logThrottled: _.throttle((...msg) => context.log(...msg), agents.settings.logThrottle),
	warn: (...msg) => agents.emit('warn', session, ...msg),
	});

[mryellow]

Unable to duplicate within agents testbed.

https://github.com/MomsFriendlyDevCo/agents/tree/fix-6

388ce55