Rename class dragHandle to drag-handle

app/assets/javascripts/vue_shared/components/panel_resizer.vue

@@ -84,7 +84,7 @@
   <div
     :class="className"
     :style="cursorStyle"
-    class="dragHandle"
+    class="drag-handle"
     @mousedown="startDrag"
     @dblclick="resetSize"
   ></div>

app/assets/stylesheets/pages/repo.scss

@@ -781,7 +781,7 @@
   }
 }
 
-.dragHandle {
+.drag-handle {
   position: absolute;
   top: 0;
   bottom: 0;

spec/javascripts/vue_shared/components/panel_resizer_spec.js

@@ -29,7 +29,7 @@ describe('Panel Resizer component', () => {
     });
 
     expect(vm.$el.tagName).toEqual('DIV');
-    expect(vm.$el.getAttribute('class')).toBe('dragHandle dragleft');
+    expect(vm.$el.getAttribute('class')).toBe('drag-handle dragleft');
     expect(vm.$el.getAttribute('style')).toBe('cursor: ew-resize;');
   });
 
@@ -40,7 +40,7 @@ describe('Panel Resizer component', () => {
     });
 
     expect(vm.$el.tagName).toEqual('DIV');
-    expect(vm.$el.getAttribute('class')).toBe('dragHandle dragright');
+    expect(vm.$el.getAttribute('class')).toBe('drag-handle dragright');
   });
 
   it('drag the resizer', () => {