Upgrade dependencies

[Michael-F-Bryan]

No description provided.

[celinval]

Hi @Michael-F-Bryan, are you planning to merge this change? I just tried installing the latest version and I get a warning that one of the dependencies have been yanked:

$ cargo install mdbook-linkcheck --version "^0.7" --locked
    Updating crates.io index
 Downloading crates ...
  Downloaded mdbook-linkcheck v0.7.7
  Installing mdbook-linkcheck v0.7.7
    Updating crates.io index
warning: package `textwrap v0.15.1` in Cargo.lock is yanked in registry `crates-io`, consider running without --locked
    Updating crates.io index
warning: package `textwrap v0.15.1` in Cargo.lock is yanked in registry `crates-io`, consider running without --locked
...

Thanks

[Mrmaxmeier]

Friendly bump 🙂
The current release of mdbook-linkcheck doesn't build on nightly because of an outdated proc-macro2 dependency:

error[E0635]: unknown feature `proc_macro_span_shrink`
  --> ~/.cargo/registry/src/index.crates.io-6f17d22bba15001f/proc-macro2-1.0.46/src/lib.rs:92:30
   |
92 |     feature(proc_macro_span, proc_macro_span_shrink)
   |                              ^^^^^^^^^^^^^^^^^^^^^^

[marxin]

Sub-package update: Michael-F-Bryan/linkcheck#11.

[marxin]

I forked the project and made package update: https://github.com/marxin/mdbook-linkcheck2.