Revert of Cross-repo recipe package system.

scripts/slave/recipe_modules/raw_io/test_api.py

+from recipe_engine import recipe_test_api
+
+class RawIOTestApi(recipe_test_api.RecipeTestApi): # pragma: no cover
+  @recipe_test_api.placeholder_step_data
+  @staticmethod
+  def output(data, retcode=None):
+    return data, retcode
+
+  @recipe_test_api.placeholder_step_data
+  @staticmethod
+  def output_dir(files_dict, retcode=None):
+    assert type(files_dict) is dict
+    assert all(type(key) is str for key in files_dict.keys())
+    assert all(type(value) is str for value in files_dict.values())
+    return files_dict, retcode
+
+  def stream_output(self, data, stream='stdout', retcode=None):
+    ret = recipe_test_api.StepTestData()
+    assert stream in ('stdout', 'stderr')
+    setattr(ret, stream, self.output(data, retcode).unwrap_placeholder())
+    return ret