Add 1.4.0 release date

danielnelson · danielnelson · commit 34b7a4c3611d · 2017-09-05T17:15:06.000-07:00
(cherry picked from commit ab1c11b)
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## v1.4 [unreleased]
+## v1.4 [2017-09-05]
 
 ### Release Notes
 
