Function check_now 

pub fn check_now(
    dir: &Path,
    base: &str,
    ours: &str,
    theirs: &str,
    result: &str,
    now: &str,
) -> Result<Vec<Violation>, Box<dyn Error>>

check, keeping only the violations that hold at now too (the branch as it is now: a later commit that put the change back counts).