Babel 6 Loose? -- Move to normal

[sldavidson]

See da-webpack #44

[sldavidson]

I have run into a error with es2015-Loose settings.

const a = [1,2,2,3,4];
const s = new Set(a);
console.log([...s]) 

That should output [1,2,3,4] but instead get [Set]

Testing this on the Babel site confirms this.

[andrewjensen]

+1 let's move to the normal es2015 preset.

[bmbarker90]

Should we remove the stage-1 preset as well? That seems very bleeding-edge to me. A good example is that transform-class-constructor-call (included in stage-1) has been denied by TC-39 and deprecated by babel