Ensure that bundling errors make are surfaced. Fixes gh-441

[rwaldron]

No description provided.

[johnnyman727]

A bunch of other places in the code return a string for a warning and an actual Error for a more stern error output. Why not return an Error here?

[rwaldron]

Because those are all taking the easy path that automatically logs with logs.warn, not logs.err. I explicitly wanted logs.err and this was the only way to force it to happen, because:

t2-cli/bin/tessel-2.js

Lines 290 to 307 in e7299f0

	module.exports.closeFailedCommand = function(opts, err) {
	if (!err) {
	err = opts;
	opts = {};
	}
	if (err instanceof Error) {
	throw err;
	} else {
	// Print a stern warning by default
	opts.type = opts.type || 'warn';
	logs[opts.type](err);
	}
	if (opts.code === undefined) {
	opts.code = 1;
	}
	process.exit(opts.code);
	};

[HipsterBrown]

This makes browserify even more helpful for warning developers about syntax errors before pushing to Tessel. Looks good to me. 👍