Don't include script and style elements in innerText

JSDOM doesn't support `innerText` [1], so our shim was just forwarding
`textContent`. Instead, remove `script` and `style` elements, which
won't do the same thing as in the browser but will hopefully remove most
unwanted content.

Addresses #111

[1] jsdom/jsdom#1245

src/translation/translate.js

@@ -63,7 +63,13 @@ Object.defineProperty(Attr.interface.prototype, 'innerText', {
 });
 var Node = require('jsdom/lib/jsdom/living/generated/Node');
 Object.defineProperty(Node.interface.prototype, 'innerText', {
-	get: function() { return this.textContent },
+	get: function() {
+		// innerText in the browser is more sophisticated, but this removes most unwanted content
+		// https://github.com/jsdom/jsdom/issues/1245#issuecomment-584677454
+		var el = this.cloneNode(true);
+		el.querySelectorAll('script,style').forEach(s => s.remove())
+		return el.textContent
+	},
 	set: function(value) { this.textContent = value },
 	configurable: true,
 });