add a mypy config file

Author: willingc

mypy.ini

@@ -0,0 +1,13 @@
+# Global options:
+
+[mypy]
+python_version = 3.6
+warn_return_any = True
+warn_unused_configs = True
+ignore_missing_imports = True
+
+# Per-module options:
+
+[mypy-bookstore._version]
+ignore_errors = True
+