Build: Prepare 2.9.0 release, including authors and history update

Add various names to mailmap so that they don't result in
duplicate entries from grunt-authors, using the existing entries
as canonical to make only the smallest change to AUTHORS.txt.

Closes #1363.

.mailmap

@@ -91,3 +91,7 @@ Dave K. Smith <[email protected]>
 David Vollbracht <[email protected]>
 Jochen Ulrich <[email protected]>
 Michał Gołębiowski-Owczarek <[email protected]>
+Leonardo Balter <[email protected]>
+Kevin Partington <[email protected]>
+Kevin Partington <[email protected]> <[email protected]>
+Manoj Kumar <[email protected]> <[email protected]>

AUTHORS.txt

@@ -128,8 +128,8 @@ Daniel De Jager <[email protected]>
 Brahim Arkni <[email protected]>
 Cory Forsyth <[email protected]>
 Ed <[email protected]>
-yagni <[email protected]>
 Manoj Kumar <[email protected]>
+yagni <[email protected]>
 Tobias Oetzel <[email protected]>
 Ray Tiley <[email protected]>
 Dustin Specker <[email protected]>

History.md

@@ -1,3 +1,13 @@
+2.9.0 / 2019-01-06
+==================
+
+  * Assert: Report RegExp/Error as strings from `rejects()`/`throws()` (#1333)
+  * Build: Add macOS and Windows to the Travis CI test matrix
+  * Build: Update engine requirement package.json to Node 6
+  * CLI: Reduce size of the dependencies tree (#1342)
+  * CLI: Re-implement run.watch() with 'node-watch' instead of 'sane' (#1342)
+  * HTML Reporter: Fix an unescaped details.source (#1341)
+
 2.8.0 / 2018-11-02
 ==================
 

package.json

@@ -2,7 +2,7 @@
   "name": "qunit",
   "title": "QUnit",
   "description": "An easy-to-use JavaScript Unit Testing framework.",
-  "version": "2.8.1-pre",
+  "version": "2.9.0-pre",
   "homepage": "https://qunitjs.com",
   "author": {
     "name": "jQuery Foundation and other contributors",