It seems to be useful to implement a "is_ancestor" workaround for git versions smaller 1.8 See https://github.com/MetricsGrimoire/RepositoryHandler/pull/11 and https://github.com/MetricsGrimoire/RepositoryHandler/commit/44bed8ec06b38e0b78612a99a7d13e9acb3029c7 /cc @sduenas @linzhp
