Bump version for new release

composer.json

@@ -1,7 +1,7 @@
 {
     "name": "ixudra/curl",
     "description": "Custom PHP Curl library for the Laravel 5 framework - developed by Ixudra",
-    "version": "6.15.1",
+    "version": "6.16.0",
     "keywords": ["Ixudra", "Laravel", "Curl"],
     "homepage": "http://ixudra.be",
     "license": "MIT",