Fix React warning about key and GitHub red code.

Author: dev-geddy

src/pages/Picture.js

@@ -10,7 +10,7 @@ class Picture extends Component {
         <article>
           <h2>Picture details</h2>
           <h3>{pictures[pictureIndex].name}</h3>
-          <p>It's only about a single picture.</p>
+          <p>It is only about a single picture.</p>
           <div>
             <img src={pictures[pictureIndex].url} alt="Nice one"/>
           </div>

src/pages/Pictures.js

@@ -6,7 +6,7 @@ import './Pictures.css'
 const RenderPictures = (picturesList) => {
   return picturesList.map((picture, index) => {
     return (
-      <div className="Picture">
+      <div className="Picture" key={`MyPicture_${index}`}>
         <img src={picture.url} alt={picture.name}/>
         <div className="Picture-name">{picture.name}</div>
         <div className="Picture-details-link">