Bump to 0.5.3

Author: FichteFoll

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name='ass',
-    version="0.5.2",
+    version="0.5.3",
     description="A library for parsing and manipulating Advanced SubStation Alpha subtitle files.",
     long_description=long_description,
     long_description_content_type="text/markdown",