Update version to v2.2.0

New features:
- DynamicBuffer can now be moved to and from String
- DynamicBuffer can be copied from SharedBuffer
- AsyncWebSocket interface is updated to use DynamicBuffer, clarifying
  ownership semantics

Fixes:
- contentTypeFor: Fix handling when extension not found
- Fix warnings on ESP32 when debug prints are enabled

library.json

@@ -19,7 +19,7 @@
     "type": "git",
     "url": "https://github.com/Aircoookie/ESPAsyncWebServer.git"
   },
-  "version": "2.1.0",
+  "version": "2.2.0",
   "license": "LGPL-3.0",
   "frameworks": "arduino",
   "platforms": ["espressif8266", "espressif32"],

library.properties

@@ -1,5 +1,5 @@
 name=ESP Async WebServer
-version=2.1.0
+version=2.2.0
 author=Me-No-Dev, willmmiles, Aircoookie
 maintainer=Aircoookie
 sentence=Async Web Server for ESP8266 and ESP31B (WLED fork)