[SEBA-412] Automated reformat of Python code

Passes of modernize, autopep8, black, then check with flake8

flake8 + manual fixes:
  lib/xos-config
  lib/xos-kafka
  lib/xos-util
  xos/coreapi
  xos/api
  xos/xos_client

Change-Id: Ib23cf84cb13beb3c6381fa0d79594dc9131dc815
diff --git a/lib/xos-config/xosconfig/__init__.py b/lib/xos-config/xosconfig/__init__.py
index d4e8305..9a0b30c 100644
--- a/lib/xos-config/xosconfig/__init__.py
+++ b/lib/xos-config/xosconfig/__init__.py
@@ -13,3 +13,5 @@
 # limitations under the License.
 
 from .config import Config
+
+__all__ = ["Config"]