Update the CodeMirror version in 2.13 release notes

Change from 5.13.4 to 5.14.2.

Change-Id: I7c3e3d44d7aea0770bf425dd81c479639b17e548
diff --git a/ReleaseNotes/ReleaseNotes-2.13.txt b/ReleaseNotes/ReleaseNotes-2.13.txt
index 68a7ea2..071dc30 100644
--- a/ReleaseNotes/ReleaseNotes-2.13.txt
+++ b/ReleaseNotes/ReleaseNotes-2.13.txt
@@ -82,7 +82,7 @@
 Upgrades
 --------
 
-* Upgrade CodeMirror to 5.13.4
+* Upgrade CodeMirror to 5.14.2
 
 * Upgrade Guava to 19.0