Audit log level of error messages

[Shadowfiend]

At least some logs are spitting errors out at INFO level (which in our case really means spitting them to standard out instead of standard error). We should look into it and fix that. Here's an example in stack driver, where we have something prefixed with ERROR that actually got sent to standard out and thus not recognized.

It's possible to handle this properly we'll actually need to either do some configuration tweaking to the logger, or switch to a different logger, maybe one that knows how to talk directly to stack driver in addition to printing to the console.

[Shadowfiend]

Going to move this into https://github.com/thesis/hubot since it's best handled in the Hubot logger.