Bump version to 1.2.0

Author: OttoWinter

library.json

@@ -12,7 +12,7 @@
     "type": "git",
     "url": "https://github.com/OttoWinter/AsyncTCP.git"
   },
-  "version": "1.1.1",
+  "version": "1.2.0",
   "license": "LGPL-3.0",
   "frameworks": "arduino",
   "platforms": "espressif32",