Bump version (#45)

Author: mhamer-bw

setup.py

@@ -12,7 +12,7 @@
 
 setup(
     name='bandwidth-sdk',
-    version='13.0.0',
+    version='13.1.0',
     description='Bandwidth\'s set of APIs',
     long_description=long_description,
     long_description_content_type="text/markdown",