Set version to 6.0.0

appveyor.yml

@@ -1,4 +1,4 @@
-version: 5.13.1.{build}
+version: 6.0.0.{build}
 environment:
   matrix:
   - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017

library.json

@@ -7,7 +7,7 @@
     "type": "git",
     "url": "https://github.com/bblanchon/ArduinoJson.git"
   },
-  "version": "5.13.1",
+  "version": "6.0.0",
   "authors": {
     "name": "Benoit Blanchon",
     "url": "https://blog.benoitblanchon.fr"

library.properties

@@ -1,5 +1,5 @@
 name=ArduinoJson
-version=5.13.1
+version=6.0.0
 author=Benoit Blanchon <blog.benoitblanchon.fr>
 maintainer=Benoit Blanchon <blog.benoitblanchon.fr>
 sentence=An efficient and elegant JSON library for Arduino.