Update snapshot description

Be more clear on what to expect
from the snapshot.

spec/frontend/vue_mr_widget/components/states/__snapshots__/mr_widget_pipeline_failed_spec.js.snap

 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`PipelineFailed should display correctly 1`] = `
+exports[`PipelineFailed should render error message with a disabled merge button 1`] = `
 <div
   class="mr-widget-body media"
 >

spec/frontend/vue_mr_widget/components/states/mr_widget_pipeline_failed_spec.js

@@ -20,7 +20,7 @@ describe('PipelineFailed', () => {
     wrapper = null;
   });
 
-  it('should display correctly', () => {
+  it('should render error message with a disabled merge button', () => {
     expect(wrapper.element).toMatchSnapshot();
   });