migrated Ellipse test to Mocha, and finished up context wrapper methods

tests/js/unit/shapes/ellipseTests.js

@@ -1,21 +0,0 @@
-Test.Modules.ELLIPSE = {
-    'add ellipse': function(containerId) {
-        var stage = new Kinetic.Stage({
-            container: containerId,
-            width: 578,
-            height: 200
-        });
-        var layer = new Kinetic.Layer();
-        var ellipse = new Kinetic.Ellipse({
-            x: stage.getWidth() / 2,
-            y: stage.getHeight() / 2,
-            radius: [70, 35],
-            fill: 'green',
-            stroke: 'black',
-            strokeWidth: 8
-        });
-        layer.add(ellipse);
-        stage.add(layer);
-        test(ellipse.getClassName() === 'Ellipse', 'shape type should be Ellipse');
-    }
-};