Function safe_app::run

pub fn run<F, I, T>(app: &App, f: F) -> Result<T, AppError> where
    F: FnOnce(&AppClient, &AppContext) -> I + Send + 'static,
    I: IntoFuture<Item = T, Error = AppError> + 'static,
    T: Send + 'static, 

Helper to execute a future by blocking the thread until the result arrives.