Release 2.2.18

Author: akarnokd

Diff for: CHANGES.md

@@ -2,6 +2,14 @@
 
 The changelog of version 1.x can be found at https://github.com/ReactiveX/RxJava/blob/1.x/CHANGES.md
 
+### Version 2.2.18 - February 21, 2020 ([Maven](http://search.maven.org/#artifactdetails%7Cio.reactivex.rxjava2%7Crxjava%7C2.2.18%7C))
+
+:warning: The 2.x version line is now in **maintenance mode** and will be supported only through bugfixes until **February 28, 2021**. No new features, behavior changes or documentation adjustments will be accepted or applied to 2.x. It is recommended to migrate to [3.x](https://github.com/ReactiveX/RxJava/tree/3.x) within this time period.
+
+#### Bugfixes
+
+  - [Pull 6894](https://github.com/ReactiveX/RxJava/pull/6894): Fix `groupBy` not requesting more if a group is cancelled with buffered items.
+
 ### Version 2.2.17 - January 12, 2020 ([Maven](http://search.maven.org/#artifactdetails%7Cio.reactivex.rxjava2%7Crxjava%7C2.2.17%7C))
 
 #### Bugfixes