docs: prepare 2.2.0 CHANGELOG for release

- Renames 2.2.1 changelog entry to 2.2.0 (not sure how it got bumped to 2.2.1!)
- Adds date for 2.2.0 release.
- Removes empty changelog entry for 2.1.6.

Author: weierophinney

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 All notable changes to this project will be documented in this file, in reverse chronological order by release.
 
-## 2.2.1 - TBD
+## 2.2.0 - 2019-11-12
 
 ### Added
 
@@ -46,28 +46,6 @@ All notable changes to this project will be documented in this file, in reverse
 
 - Nothing.
 
-## 2.1.6 - TBD
-
-### Added
-
-- Nothing.
-
-### Changed
-
-- Nothing.
-
-### Deprecated
-
-- Nothing.
-
-### Removed
-
-- Nothing.
-
-### Fixed
-
-- Nothing.
-
 ## 2.1.5 - 2019-10-10
 
 ### Added