docs: updated CHANGELOG.md (#6348)

Signed-off-by: GitHub <noreply@github.com>

Co-authored-by: sarabala1979 <sarabala1979@users.noreply.github.com>

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Changelog
 
+## v3.1.2 (2021-07-15)
+
+ * [98721a96e](https://github.com/argoproj/argo-workflows/commit/98721a96eef8e4fe9a237b2105ba299a65eaea9a) fixed test
+ * [6041ffe22](https://github.com/argoproj/argo-workflows/commit/6041ffe228c8f79e6578e097a357dfebf768c78f) fix(controller): Not updating StoredWorkflowSpec when WFT changed during workflow running (#6342)
+ * [d14760182](https://github.com/argoproj/argo-workflows/commit/d14760182851c280b11d688b70a81f3fe014c52f) fix(cli): v3.1 Argo Auth Token (#6344)
+ * [ce5679c4b](https://github.com/argoproj/argo-workflows/commit/ce5679c4bd1040fa5d68eea24a4a82ef3844d43c) feat(controller): Store artifact repository in workflow status. Fixes
+ * [74581157f](https://github.com/argoproj/argo-workflows/commit/74581157f9fd8190027021dd5af409cd3e3e781f) fix(executor): Tolerate docker re-creating containers. Fixes #6244 (#6252)
+ * [cd208e27f](https://github.com/argoproj/argo-workflows/commit/cd208e27ff0e45f82262b18ebb65081ae5978761) fix(executor): emissary - make /var/run/argo files readable from non-root users. Fixes #6238 (#6304)
+
+### Contributors
+
+ * Alex Collins
+ * Saravanan Balasubramanian
+ * Yuan (Bob) Gong
+
 ## v3.1.1 (2021-06-28)
 
  * [4d12bbfee](https://github.com/argoproj/argo-workflows/commit/4d12bbfee13faea6d2715c809fab40ae33a66074) fix(conttroller): Always set finishedAt dote. Fixes #6135 (#6139)