Bump version to 0.5.3

Author: ThiefMaster

setup.py

@@ -36,7 +36,7 @@ def _build_assets(self):
 
 setup(
     name='maildump',
-    version='0.5.2',
+    version='0.5.3',
     description='An SMTP server that makes all received mails accessible via a web interface and REST API.',
     long_description=readme,
     url='https://github.com/ThiefMaster/maildump',