Update setup.py

Updated version to 3.0.6 in setup.py

Author: Johannestegner

setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name='personnummer',
-    version='3.0.4',
+    version='3.0.6',
     description='Validate Swedish personal identity numbers',
     url='http://github.com/personnummer/python',
     author='Personnummer and Contributors',