Add init files for modularization, generated using mkinit (now a dependency on dev)

src/pg_rad/exceptions/__init__.py

@@ -0,0 +1,10 @@
+# do not expose internal logger when running mkinit
+__ignore__ = ["logger"]
+
+from pg_rad.exceptions import exceptions
+
+from pg_rad.exceptions.exceptions import (ConvergenceError, DataLoadError,
+                                          InvalidCSVError,)
+
+__all__ = ['ConvergenceError', 'DataLoadError', 'InvalidCSVError',
+           'exceptions']