add error handlers

minor/app.py

 from flask import Flask
 from minor.controller import ApiController, MusicController
-
+from minor.error_handlers import set_error_handlers
 
 class App(object):
     def __init__(self, config):
         self._flask = Flask(__name__)
         self._flask.config['MONGODB_SETTINGS'] = {'db': 'minor'}       
         self._flask.config.update(config)
+        set_error_handlers(self._flask)
 
         from minor.model import db
         db.init_app(self._flask)

minor/error_handlers.py

+from flask import jsonify
+
+def set_error_handlers(app):
+    @app.errorhandler(404)
+    def four_o_four(e):
+        return jsonify({"code": 404, "msg": "not found"}), 404
+
+    @app.errorhandler(500)
+    def five_hundred(e):
+        return jsonify({"code": 500, "msg": "internal error"}), 500
+
+    @app.errorhandler(403)
+    def verboten(e):
+        return jsonify({"code": 403, "msg": "verboten"}), 403