update changelog and set version to 2.0.0

CHANGELOG.md

@@ -1,3 +1,8 @@
+2.0.0
+- Drop support for API V1. Defaults to API V2.
+- Add retain flag option to mqtt on_message
+- Add support for Python3
+
 0.9.0
 ----
 Author: Tony DiCola
@@ -9,4 +14,4 @@ Author: Tony DiCola
 
 0.0.1
 ----
-Initial Changelog
+Initial Changelog

setup.py

@@ -16,7 +16,7 @@ classifiers = ['Development Status :: 4 - Beta',
 
 setup(
     name             = 'adafruit-io',
-    version          = '1.1.1',
+    version          = '2.0.0',
     author           = 'Justin Cooper',
     author_email     = 'justin@adafruit.com',
     packages         = ['Adafruit_IO'],