Preparing release 5.3a1.dev0

Author: Michael Howitz

CHANGES.rst

@@ -1,8 +1,8 @@
 Changes
 =======
 
-5.3 (unreleased)
-----------------
+5.3a1.dev0 (2022-04-13)
+-----------------------
 
 - Allow to use the package with Python 3.11 -- Caution: No security audit has
   been done so far.

setup.py

@@ -32,7 +32,7 @@ def read(*rnames):
 
 setup(
     name='RestrictedPython',
-    version='5.3.dev0',
+    version='5.3a1.dev0',
     url='https://github.com/zopefoundation/RestrictedPython',
     license='ZPL 2.1',
     description=(