Update greeting in index.html

Related to yeoman/yeoman#770

app/index.js

@@ -130,7 +130,7 @@ AppGenerator.prototype.writeIndex = function writeIndex() {
   var contentText = [
     '        <div class="container" style="margin-top:50px">',
     '            <div class="hero-unit">',
-    '                <h1>Wotcha!</h1>',
+    '                <h1>\'Allo, \'Allo!</h1>',
     '                <p>You now have</p>',
     '                <ul>'
   ];