Remove babel-register

[danneu]

I was too eager to test my react-template-render library in koa-skeleton and thus replaced my Pug templates with .jsx templates. But now I need Babel to compile .jsx into .js.

The easiest solution was to use babel-register:

koa-skeleton/src/index.js

Lines 4 to 7 in 30ccf95

	require('babel-register')({
	presets: ['react'],
	extensions: ['.jsx'],
	})

But it brings a thick runtime dependency, probably slows down large project boot, and probably degrades the quality of stack traces.

Better would be to compile .jsx to .js physically with a watch script.

It's kind of lame to have a build step at all on a server, but so far .jsx templates have been worth it. Prob on par with what I had with Pug.