Fix mux route patterns
Fix mux route patterns

The regexes on the mux routes are non-functional with the
latest changes on gorilla/mux. Fixes #7.

Signed-off-by: Ahmet Alp Balkan <787aefc6cbd2e3e8663c1f03b44afee9126bfa5e@gmail.com>

ahmetalpbalkan/go-httpbin