Update composer.

composer.lock

@@ -493,16 +493,16 @@
         },
         {
             "name": "symfony/console",
-            "version": "v3.4.1",
+            "version": "v3.4.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/console.git",
-                "reference": "2cdef78de8f54f68ff16a857e710e7302b47d4c7"
+                "reference": "9f21adfb92a9315b73ae2ed43138988ee4913d4e"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/console/zipball/2cdef78de8f54f68ff16a857e710e7302b47d4c7",
+                "url": "https://api.github.com/repos/symfony/console/zipball/9f21adfb92a9315b73ae2ed43138988ee4913d4e",
-                "reference": "2cdef78de8f54f68ff16a857e710e7302b47d4c7",
+                "reference": "9f21adfb92a9315b73ae2ed43138988ee4913d4e",
                 "shasum": ""
             },
             "require": {
@@ -558,20 +558,20 @@
             ],
             "description": "Symfony Console Component",
             "homepage": "https://symfony.com",
-            "time": "2017-12-02T18:20:11+00:00"
+            "time": "2017-12-14T19:40:10+00:00"
         },
         {
             "name": "symfony/debug",
-            "version": "v3.4.1",
+            "version": "v3.4.2",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/debug.git",
-                "reference": "fb2001e5d85f95d8b6ab94ae3be5d2672df128fd"
+                "reference": "543deab3ffff94402440b326fc94153bae2dfa7a"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/debug/zipball/fb2001e5d85f95d8b6ab94ae3be5d2672df128fd",
+                "url": "https://api.github.com/repos/symfony/debug/zipball/543deab3ffff94402440b326fc94153bae2dfa7a",
-                "reference": "fb2001e5d85f95d8b6ab94ae3be5d2672df128fd",
+                "reference": "543deab3ffff94402440b326fc94153bae2dfa7a",
                 "shasum": ""
             },
             "require": {
@@ -614,7 +614,7 @@
             ],
             "description": "Symfony Debug Component",
             "homepage": "https://symfony.com",
-            "time": "2017-11-21T09:01:46+00:00"
+            "time": "2017-12-12T08:27:14+00:00"
         },
         {
             "name": "symfony/polyfill-mbstring",