Use better keys in example code

Author: iansinnott

example/index.js

@@ -18,18 +18,18 @@ const Demo = React.createClass({
     let replacedText;
 
     // Match URLs
-    replacedText = reactStringReplace(text, /(https?:\/\/\S+)/g, match => (
-      <a key={match} href={match}>{match}</a>
+    replacedText = reactStringReplace(text, /(https?:\/\/\S+)/g, (match, i) => (
+      <a key={match + i} href={match}>{match}</a>
     ));
 
     // Match @-mentions
-    replacedText = reactStringReplace(replacedText, /@(\w+)/g, match => (
-      <a key={match} href={`https://twitter.com/${match}`}>@{match}</a>
+    replacedText = reactStringReplace(replacedText, /@(\w+)/g, (match, i) => (
+      <a key={match + i} href={`https://twitter.com/${match}`}>@{match}</a>
     ));
 
     // Match hashtags
-    replacedText = reactStringReplace(replacedText, /#(\w+)/g, match => (
-      <a key={match} href={`https://twitter.com/hashtag/${match}`}>#{match}</a>
+    replacedText = reactStringReplace(replacedText, /#(\w+)/g, (match, i) => (
+      <a key={match + i} href={`https://twitter.com/hashtag/${match}`}>#{match}</a>
     ));
 
     return (