change URLs in releases-pages to remove unnecessary redirect

[syphar]

stumbled on this while testing around.

The release-pages link to the docs without the trailing /, and the rustdoc page then appends the / with a redirect.

Not not any more

[jyn514]

Looks like you need to update the tests:

 thread 'web::releases::tests::releases_homepage_and_recent' panicked at 'assertion failed: `(left == right)`
  left: `"/crate_that_succeeded_with_github/0.2.0/crate_that_succeeded_with_github/"`,
 right: `"/crate_that_succeeded_with_github/0.2.0/crate_that_succeeded_with_github"`', src/web/releases.rs:1238:17

Looks fine other than that, though :)

[syphar]

@jyn514 damnit, the one time I don't run them locally 😆

[syphar]

updated them now

[syphar]

also rebased on master, to fixed the last test failure