Reject uploads with unchanged default lib.rs

[Kijewski]

Wouldn't it be useful to reject uploads where the lib.rs contains nothing but the default contents of a new library? These uploads are obviously either tests or accidents.

#[cfg(test)]
mod tests {
    #[test]
    fn it_works() {
        let result = 2 + 2;
        assert_eq!(result, 4);
    }
}

If someone wants to claim a name, then they can still (at least) add a comment to the file.