Right click test, buttons instead button, test updated

Author: Alex Vinober

src/components/dragelement/index.js

@@ -78,7 +78,7 @@ dragElement.init = function init(options) {
     element.ontouchstart = onStart;
 
     function onStart(e) {
-        if(e.button && e.button === 2) {    // right click
+        if(e.buttons && e.buttons === 2) {    // right click
             return;
         }
 

test/jasmine/tests/dragelement_test.js

@@ -130,8 +130,7 @@ describe('dragElement', function() {
         var options = { element: this.element, gd: this.gd };
         dragElement.init(options);
 
-        options.element.onmousedown({button: 2})
-
+        mouseEvent('mousedown', this.x, this.y, { buttons: 2 });
         expect(countCoverSlip()).toEqual(0);
     });