update README and CHANGELOG

CHANGELOG.md

@@ -1,4 +1,5 @@
 # 1.6.0
+- No changes other than fixes for non-backwards compatible Flutter changes 
 - Flutter `>= 1.13.0` is required due to Flutter compatibility issues
 - Dart `>= 2.6.0` is required
 

README.md

@@ -7,6 +7,8 @@ The brightest, hippest, coolest router for Flutter.
 [![Build Status](https://travis-ci.org/theyakka/fluro.svg?branch=master)](https://travis-ci.org/theyakka/fluro)
 [![Coverage](https://codecov.io/gh/theyakka/fluro/branch/master/graph/badge.svg)](https://codecov.io/gh/theyakka/fluro)
 
+Version `1.6.0` requires Flutter `>= 1.13.0` and Dart `>= 2.6.0`. If you're running an older version of Flutter, use a version `< 1.6.0`.
+
 ## Features
 
 - Simple route navigation