Finished Checkin/out feature for now

-Checkin/out api methods can be used while signed in
-Added checkout button in Netzke App, which also signs out in addition to checking out.

app/components/app_tab_panel/javascripts/sign_out.js

@@ -5,5 +5,17 @@
        url: '/users/sign_out',
        method: 'DELETE'
     });
+  },
+  onCheckOut: function(){
+    Ext.Ajax.request({
+       url: '/api/v1/checkout',
+       method: 'POST',
+       success: function(response, opts) {
+         Ext.Ajax.request({
+            url: '/users/sign_out',
+            method: 'DELETE'
+         });
+       }
+    });
   }
 }