prep for release (#156)

Co-authored-by: Scott Barnhart <[email protected]>

CHANGELOG.md

@@ -3,7 +3,7 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [6.1.2] - TBD
+## [6.1.2] - 2020-05-07
 ### Changed
 - Change type of `apiary_managed_schemas` from `list(any)` to `list(map(string))` to support dynamically-generated schema lists. This type is backward-compatible with previous schema lists.  Schema lists were already lists of maps of strings, but this change makes TF 0.12 work in certain circumstances that were causing a fatal TF error.