Move the `clone_on_copy` lint from the complexity group to the style group?

Right now, the [`clone_on_copy`](https://rust-lang.github.io/rust-clippy/master/index.html#clone_on_copy) lint is in the complexity lint group, but it seems like perhaps it should be in the style lint group. I think the same for [`char_lit_as_u8`](https://rust-lang.github.io/rust-clippy/master/index.html#char_lit_as_u8). Thoughts?