pub(crate)
pub
Eventually, there will probably be a `crate` visibility specifier that does the same thing as `pub(crate)`. This commit replaces `pub` with `pub(crate)`, so when `crate` is available we can easily switch to it.
- Upgrade to rust 2018 - Update dependencies - Use BTree{Map,Set} instead of Map and Set
Format with rustfmt
