Clean up utils.py to use database

Uses of the original library_stats dictionary in utils.py were either removed or commented out, replaced by the saving of models into the database.

spotifyvis/static/spotifyvis/scripts/test_db.js

@@ -1,10 +1,4 @@
-console.log("{{ user_id }}");
-artist_data = JSON.parse('{{ artist_data }}');
-artist_data.forEach(function(d) {
-	console.log(d.name, d.num_songs);
-});
-
-d3.json("{% url "get_artist_data" user_id %}", function(error, data) {
+d3.json("{% url "get_artist_data", user_id %}").then(function(error, data) {
 	data.forEach(function(d) {
 		console.log(d.name, d.num_songs);
 	});