Add test snippet for classes as testf

snippets.json

@@ -205,5 +205,27 @@
       "});",
       "/* eslint-enable */"
     ]
+  },
+  "Blank functional test": {
+    "prefix": "testf",
+    "body": [
+      "/* eslint-disable import/first */",
+      "import React from 'react';",
+      "import renderer from 'react-test-renderer';",
+      "$2",
+      "import $1 from '../$1';",
+      "$2",
+      "it('renders a $1', () => {",
+      "  const component = renderer.create(<$1 />);",
+      "  expect(component).toMatchSnapshot();",
+      "$2",
+      "  const instance = component.getInstance();",
+      "});",
+      "$2",
+      "it('renders a $1 with no props', () => {",
+      "  expect(renderer.create(<$1 />)).toMatchSnapshot();",
+      "});",
+      "/* eslint-enable */"
+    ]
   }
 }