* Add anchor existant checking to link_checker component
* Oops, forgot some changes
* Drop scraper dependency and rework tests
* Handle name attributes
As mentioned in #381, crates.io 404's any request without an Accept:
text/html header. It 200's any request with one, but at least
false-successes don't prevent checking any other links.
This also makes it easier to add a custom User-Agent if desired.
rustfmt and fix a clippy nit (unnecessary return) while I'm here.
