Use btn-med-size for Cancel button on installation page

Author: dgolovin

browser/pages/install/install.html

@@ -51,6 +51,6 @@ <h4 class="modal-title" id="myModalLabel">&nbsp;</h4>
 
 <footer class="no-background-color">
   <div class="footer-border"></div>
-  <button type="button" id="location-cancel-btn" class="go-btn footer-btns btn btn-primary btn-lg" form="installForm"
+  <button type="button" id="location-cancel-btn" class="go-btn footer-btns btn btn-primary btn-lg btn-med-size" form="installForm"
           ng-click="instCtrl.exit()">Cancel</button>
 </footer>