fix typo

Author: IvanBisultanov

demo/material/css/angular-data-grid.material.css

@@ -2,7 +2,7 @@ th:focus,
 a:focus {
   outline: none; }
 
-.codepen-wtap {
+.codepen-wrap {
   margin-top: 15px; }
 
 .mdl-data-table {

demo/material/index.html

@@ -166,7 +166,7 @@ <h4>Angular Data Grid sample using Material Design styling</h4>
             </div>
             <hr>
             <md-button class="md-raised md-primary" ng-click="showCode = !showCode">CodePen</md-button>
-            <div ng-show="showCode" class="codepen-wtap">
+            <div ng-show="showCode" class="codepen-wrap">
                 <p data-height="768" data-theme-id="21603" data-slug-hash="jWBaOX" data-default-tab="html" data-user="IvanBisultanov" class='codepen'>See the Pen <a
                         href='http://codepen.io/IvanBisultanov/pen/jWBaOX'>jWBaOX</a> by IvanBisultanov (<a href='http://codepen.io/IvanBisultanov'>@IvanBisultanov</a>) on <a href='http://codepen.io'>CodePen</a>.
                 </p>

demo/material/scss/angular-data-grid.material.scss

@@ -4,7 +4,7 @@ th:focus,
 a:focus {
   outline: none;
 }
-.codepen-wtap {
+.codepen-wrap {
   margin-top: 15px;
 }
 .mdl-data-table {