Update Cargo.lock

[Senzaki]

Hi! Just a minor PR. Recent versions of racer have fixed very annoying bugs, especially https://github.com/racer-rust/racer/issues/916 (there is no use for "extern crate" in Rust 2018 but the version of racer used by racerd needs it to trigger completion).

I have updated Cargo.lock to include these fixes in racerd. I have also updated other dependencies, and all tests are still working (as well as YouCompleteMe, which now works properly :slightly_smiling_face: ).

[fandahao17]

Agree. Actually, the dependency "rust-ap-syntax v274.0.0" can't compile on my computer with rustc version 1.33.0.

error[E0308]: mismatched types
   --> /Users/fandahao1/.cargo/registry/src/mirrors.blah-61ef6e0cd06fb9b8/rustc-ap-syntax-274.0.0/attr/mod.rs:622:64
    |
622 |                 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
    |                                                                ^^^^^^^^ expected str, found struct `core::str::EscapeDefault`
    |
    = note: expected type `&str`
               found type `&core::str::EscapeDefault<'_>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0308`.
error: Could not compile `rustc-ap-syntax`.

The error disappeared after I changed racer version in Cargo.toml to "2.1.19".

[Senzaki]

As explained here, racer needs to be built using rust nightly, so I think you should update your nightly toolchain before building it, as the current version seems to be 1.35.0-nightly. (Also, I bumped the versions of the dependencies again, just to have the most up-to-date versions if and when this is merged. Everything seems to be still working with this new Cargo.lock.)