Try to fix node 10 unit test (#5235)

* fixed
* removed node 9

.travis.yml

@@ -64,10 +64,8 @@ jobs:
         apt:
           packages: # avoid installing packages
     - stage: Unit Tests
-      env: LAUNCHER=Node CANFAIL=TRUE
+      env: LAUNCHER=Node
       node_js: "10"
-    - stage: Unit Tests
-      node_js: "9"
     - stage: Unit Tests
       node_js: "8"
     - stage: Unit Tests

test/unit/object.js

@@ -26,25 +26,8 @@
     var elImage = _createImageElement();
     elImage.width = IMG_WIDTH;
     elImage.height = IMG_HEIGHT;
-    setSrc(elImage, IMG_SRC, function() {
-      callback(elImage);
-    });
-  }
-
-  function setSrc(img, src, callback) {
-    if (fabric.isLikelyNode) {
-      require('fs').readFile(src, function(err, imgData) {
-        if (err) {
-          throw err;
-        };
-        img.src = imgData;
-        callback && callback();
-      });
-    }
-    else {
-      img.src = src;
-      callback && callback();
-    }
+    elImage.onload = callback;
+    elImage.src = IMG_SRC;
   }
 
   QUnit.module('fabric.Object', {

test/unit/util.js

@@ -483,10 +483,13 @@
 
   QUnit.test('fabric.util.loadImage with url for a non exsiting image', function(assert) {
     var done = assert.async();
-    fabric.util.loadImage(IMG_URL_NON_EXISTING, function(img, error) {
-      assert.equal(error, true, 'callback should be invoked with error set to true');
-      done();
-    });
+    try {
+      fabric.util.loadImage(IMG_URL_NON_EXISTING, function(img, error) {
+        assert.equal(error, true, 'callback should be invoked with error set to true');
+        done();
+      }, this);
+    }
+    catch (e) { }
   });
 
   var SVG_WITH_1_ELEMENT = '<?xml version="1.0"?>\