Bump the version number

Author: junhwi

setup.py

@@ -10,7 +10,7 @@
 
 setup(
     name='slack-logger',
-    version='0.2.0',
+    version='0.3.0',
     description='A Python logging handler for Slack integration',
     long_description=long_description,
     url='https://github.com/junhwi/python-slack-logger',