Add --ignore-init-module-imports to autoflake args (#283)

Libraries often import things in __init__.py so they can be reexported
to users rather than used directly by __init__.py. These should be
ignored by autoflake.

wpiformat/wpiformat/pyformat.py

@@ -20,6 +20,7 @@ def run_batch(config_file, names):
                 "autoflake",
                 "--remove-all-unused-imports",
                 "--remove-unused-variables",
+                "--ignore-init-module-imports",
                 "--quiet",
                 "-i",
             ]