Fix compile, use hyper "full" feature

Currently the project does not compile as it's using hyper features it isn't opting into. This patch opts into the hyper full feature to fix that.

The project tests work as the dev-dependencies are opting into the features for you, but this isn't the case for users.

Reproduce

Setup a new project with just this as a dependency.

[dependencies]
wiremock = "0.4.4"

cargo check

error[E0433]: failed to resolve: could not find `Server` in `hyper`
  --> /home/alex/.cargo/registry/src/github.com-1ecc6299db9ec823/wiremock-0.4.4/src/mock_server/hyper.rs:34:25
   |
34 |     let server = hyper::Server::from_tcp(listener)
   |                         ^^^^^^ could not find `Server` in `hyper`

error[E0433]: failed to resolve: could not find `rt` in `hyper`
  --> /home/alex/.cargo/registry/src/github.com-1ecc6299db9ec823/wiremock-0.4.4/src/mock_server/hyper.rs:54:16
   |
54 | impl<F> hyper::rt::Executor<F> for LocalExec
   |                ^^ could not find `rt` in `hyper`

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0433`.
error: could not compile `wiremock`

You can also see this in-project by commenting out the dev-dependencies and running cargo check.

LukeMathWalker / wiremock-rs

Fix compile, use hyper "full" feature #48

Reproduce