remove unused jquery dependency

[micaste]

Since I can't sign the Contributor License Agreement with my current employment in order to contribute, I can't make a PR.

I just wanted to contribute by saying that the jquery dependency should be removed since it is unused, here:

extension-api-examples/src/javascript/app.js

Lines 24 to 27 in bda42a0

	var $ = require('jquery');
	SYMPHONY.remote.hello().then(function(data) {

and there:

extension-api-examples/package.json

Lines 18 to 20 in bda42a0

	"dependencies": {
	"jquery": "^3.2.1"
	}