add destroy method

[baptistebriel]

Hi,
Related to #43 & #23, I tried to add a destroy method to the Select class, and also clean up a bit the event listeners. You'll see that I edited the welcome demo with a hacky setTimeout, just to see what's done on destroy.

Basically, I just created an object with all the eventListener named functions. There's surely some enhancement to do, so we could skip the const self = this thing...

this.evnts = {
  target: {
    click() {},
    focus() {},
    blur({relatedTarget}) {},
    deviceClick(e) {}
  },
  drop: {}
  // etc...
};

So we can remove the event listeners in the destroy function.
I had a question tho; why not directly using the class to define the init method instead of doing this?

Select.init = (options={}) => {}

I've moved it inside the class. Let me know your thoughts!

[silvenon]

👍 Why does it say that you want to merge this from an unknown repository?

[baptistebriel]

Sorry for the delay @silvenon — it says that I want to merge this from an unknown repository because I deleted my fork; I finally ended up using a custom function instead of select because of major performances issues (tether/issues/148)