mkcol: Ensure presence of a trailing slash

Closes: https://github.com/dom111/webdav-js/issues/56

src/lib/UI/NativeDOM/Footer.js

@@ -33,7 +33,7 @@ export default class Footer extends Element {
         return;
       }
 
-      this.trigger('create-directory', joinPath(location.pathname, directoryName), directoryName, location.pathname);
+      this.trigger('create-directory', joinPath(location.pathname, directoryName) + '/', directoryName, location.pathname);
     });
   }
 }