Update composer lock file

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "c599c4440653c0c90f0151d0684fa35a",
+    "content-hash": "4aab6f51a8b5670157f1ac17b14a2fc7",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -6287,6 +6287,53 @@
                 "issues": "https://drupal.org/project/issues/group"
             }
         },
+        {
+            "name": "drupal/link_attributes",
+            "version": "1.9.0",
+            "source": {
+                "type": "git",
+                "url": "https://git.drupalcode.org/project/link_attributes.git",
+                "reference": "8.x-1.9"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://ftp.drupal.org/files/projects/link_attributes-8.x-1.9.zip",
+                "reference": "8.x-1.9",
+                "shasum": "efbfc869c2e0b13b1bd5c9ff01dd51d3f2a6b755"
+            },
+            "require": {
+                "drupal/core": "^8.4"
+            },
+            "type": "drupal-module",
+            "extra": {
+                "branch-alias": {
+                    "dev-1.x": "1.x-dev"
+                },
+                "drupal": {
+                    "version": "8.x-1.9",
+                    "datestamp": "1564012686",
+                    "security-coverage": {
+                        "status": "covered",
+                        "message": "Covered by Drupal's security advisory policy"
+                    }
+                }
+            },
+            "notification-url": "https://packages.drupal.org/8/downloads",
+            "license": [
+                "GPL-2.0-or-later"
+            ],
+            "authors": [
+                {
+                    "name": "larowlan",
+                    "homepage": "https://www.drupal.org/user/395439"
+                }
+            ],
+            "description": "Provides a widget to allow settings of link attributes for menu links.",
+            "homepage": "https://www.drupal.org/project/link_attributes",
+            "support": {
+                "source": "https://git.drupalcode.org/project/link_attributes"
+            }
+        },
         {
             "name": "drupal/menu_block",
             "version": "1.5.0",