Reuse vue-template-es2015-compiler to transpile component

[thgh]

vue-template-es2015-compiler is required in #7 so why not use it to transpile the whole component instead of only the templates?

1. Which option seems the most obvious? transpile: true es6: true buble: true
2. Default on?

[Jetsly]

when some es6 in component,buble is not supported

function* helloWorldGenerator() {
  yield 'hello';
  yield 'world';
  return 'ending';
}

but,you can use babel for supported,so only transpile templates

[thgh]

OK, buble compilation will be off by default.

The option will be buble: true or buble: { transforms: ... }