switch to error second callbacks

Author: shiffman

examples/NeuralNetwork-mouse-gesture/sketch.js

@@ -75,7 +75,7 @@ function mouseReleased() {
 }
 
 // Step 9: define a function to handle the results of your classification
-function gotResults(error, results) {
+function gotResults(results) {
   label = results[0].label;
   console.log(results);
 }

src/utils/callcallback.js

@@ -3,7 +3,6 @@
 // This software is released under the MIT License.
 // https://opensource.org/licenses/MIT
 
-
 /**
  * Most ml5 methods accept a callback function which will be
  * called with the arguments (error, result).
@@ -29,11 +28,11 @@ export default function callCallback(promise, callback) {
   return new Promise((resolve, reject) => {
     promise
       .then((result) => {
-        callback(undefined, result);
+        callback(result);
         resolve(result);
       })
       .catch((error) => {
-        callback(error);
+        callback(undefined, error);
         reject(error);
       });
   });