docs(ngRoute): grammar correction

grammar: occurs -> occur

Closes angular#5937

Author: allonhadaya

src/ngRoute/route.js

@@ -370,7 +370,7 @@ function $RouteProvider(){
      * @eventType broadcast on root scope
      * @description
      * Broadcasted before a route change. At this  point the route services starts
-     * resolving all of the dependencies needed for the route change to occurs.
+     * resolving all of the dependencies needed for the route change to occur.
      * Typically this involves fetching the view template as well as any dependencies
      * defined in `resolve` route property. Once  all of the dependencies are resolved
      * `$routeChangeSuccess` is fired.