Bump version to 0.4.3

Highlight of the release are returning an error status code
if the the card does not have permissions to open a door.

Author: xrmx

setup.py

@@ -8,7 +8,7 @@
 except ImportError:
     from distutils.core import setup
 
-version = '0.4.2'
+version = '0.4.3'
 
 setup(
     name='labAdmin',