Update according to Laravel 5.8 changes

Author: pactode

src/macros/joinRelation.php

@@ -7,7 +7,7 @@
 
     return $this->join(
         $relation->getRelated()->getTable(),
-        $relation->getQualifiedForeignKey(),
+        $relation->getQualifiedForeignKeyName(),
         $operator,
         $relation->getQualifiedOwnerKeyName()
     );

src/macros/leftJoinRelation.php

@@ -7,7 +7,7 @@
 
     return $this->leftJoin(
         $relation->getRelated()->getTable(),
-        $relation->getQualifiedForeignKey(),
+        $relation->getQualifiedForeignKeyName(),
         $operator,
         $relation->getQualifiedOwnerKeyName()
     );