Resolve "Add a "pick random artists" button"

Closes #23 (closed)

public/js/scripts.js

+/* pick some random artists */
+function pickRandomArtists() {
+  var pickedArtistsCount = 6 + Math.floor(Math.random() * 6);
+  var artistElements = document.getElementsByClassName("checkbox-artist");
+  for (var i = 0; i < pickedArtistsCount; i++) {
+    var random = Math.floor(Math.random() * artistElements.length);
+    artistElements[random].click();
+  }
+}