docs: add release notes for 4.2.1

docs/release-notes/release-notes-4.2.1.rst

@@ -0,0 +1,14 b''
+|RCE| 4.2.1 |RNS|
+-----------------
+
+Release Date
+^^^^^^^^^^^^
+
+- 2016-07-04
+
+Fixes
+^^^^^
+
+- ui: fixed empty labels caused by missing translation of JS components
+- login: fixed bad routing URL in comments when user is not logged in.
+- celery: make sure to run tasks in sync mode if connection to celery is lost.

docs/release-notes/release-notes.rst

@@ -9,6 +9,7 b' Release Notes'
 .. toctree::
    :maxdepth: 1
 
+   release-notes-4.2.1.rst
    release-notes-4.2.0.rst
    release-notes-4.1.2.rst
    release-notes-4.1.1.rst