use new Symfony components

Author: azeemhassni

composer.json

@@ -22,11 +22,11 @@
   },
   "require": {
     "ext-zip": "*",
-    "symfony/console": "^3.2",
-    "guzzlehttp/guzzle": "^6.2",
-    "symfony/process": "^3.2",
-    "symfony/filesystem": "^3.2",
-    "symfony/yaml": "^3.2",
+    "symfony/console": ">=3.2",
+    "guzzlehttp/guzzle": ">=6.2",
+    "symfony/process": "=>3.2",
+    "symfony/filesystem": "=>3.2",
+    "symfony/yaml": "=>3.2",
     "wp-cli/wp-cli": "^1.2"
   },
   "bin": [