Update 04-components.html (#14)

Remove `key` from the `Fragment` example

04-components.html

@@ -35,7 +35,7 @@ <h2>{data}</h2>
 }
 
 // Since React 16.0.0, components can return an array of elements as well
-// In doing so, no additional wrapper element is created.
+// In doing so, no additional wrapper element is created
 // One caveat is that, similarly to what we do when rendering an array,
 // we have to add a unique key to each element in the array
 // (we'll see more on this in the next lesson)
@@ -54,8 +54,8 @@ <h2 key="data">{data}</h2>
  var data = "world"
  return (
  <Fragment>
- <h1 key="hello">Hello</h1>
- <h2 key="data">{data}</h2>
+ <h1>Hello</h1>
+ <h2>{data}</h2>
  </Fragment>
  )
 }