fix: bump up z-index of element being dragged

Author: mattlewis92

src/draggable.directive.ts

@@ -248,7 +248,7 @@ export class DraggableDirective implements OnInit, OnChanges, OnDestroy {
               left: `${rect.left}px`,
               width: `${rect.width}px`,
               height: `${rect.height}px`,
-              zIndex: '10',
+              zIndex: '1000',
               cursor: this.dragCursor,
               margin: '0'
             });

test/draggable.directive.spec.ts

@@ -578,7 +578,7 @@ describe('draggable directive', () => {
     expect(ghostElement.style.left).to.be.ok;
     expect(ghostElement.style.width).to.be.ok;
     expect(ghostElement.style.height).to.be.ok;
-    expect(ghostElement.style.zIndex).to.equal('10');
+    expect(ghostElement.style.zIndex).to.equal('1000');
     expect(draggableElement.style.visibility).to.equal('hidden');
     expect((ghostElement as HTMLElement).hasAttribute('mwldraggable')).to.be
       .true;