Routing incorrectly matches URIs with prefixes

[david-perez]

I discovered this while testing integration with Lambda behind API Gateway, where the deployed API contains the API stage in the URI:

Both these cases fail:

#[test]
fn foo() {
    let get_server_statistics_request_spec = RequestSpec::new(
        Method::GET,
        UriSpec::new(PathAndQuerySpec::new(
            PathSpec::from_vector_unchecked(vec![PathSegment::Literal(String::from("stats"))]),
            QuerySpec::from_vector_unchecked(vec![]),
        )),
    );

    let misses = vec![
        (Method::GET, "/beta/stats"),
        (Method::GET, "/multiple/stages/in/path/stats"),
    ];
    for (method, uri) in &misses {
        assert_eq!(
            Match::No,
            get_server_statistics_request_spec.matches(&req(method, uri, None))
        );
    }
}