Fix support date for v3.1 in readme
@@ -99,7 +99,7 @@ The currently supported versions of Oscar are:
+---------+----------------+
| Version | End of support |
+=========+================+
-| 3.1 | April 2021 |
+| 3.1 | April 2022 |
+---------+----------------+
| 3.0 | May 2021 |
+---------+----------------+
