Laravel 5.6 updates

Travis config update

Removed HHVM script as Laravel no longer support HHVM after releasing 5.3

vendor/symfony/routing/RouteCollection.php

@@ -153,6 +153,23 @@ class RouteCollection implements \IteratorAggregate, \Countable
         }
     }
 
+    /**
+     * Adds a prefix to the name of all the routes within in the collection.
+     */
+    public function addNamePrefix(string $prefix)
+    {
+        $prefixedRoutes = array();
+
+        foreach ($this->routes as $name => $route) {
+            $prefixedRoutes[$prefix.$name] = $route;
+            if (null !== $name = $route->getDefault('_canonical_route')) {
+                $route->setDefault('_canonical_route', $prefix.$name);
+            }
+        }
+
+        $this->routes = $prefixedRoutes;
+    }
+
     /**
      * Sets the host pattern on all routes.
      *