Benchmarks out-of-date

[jdelmerico]

It's great that these benchmarks exist, but there should be a date associated with the running of the benchmark. It would be even better if there was also some process that ran once in a while to update these. It looks like the last run was more than a year old for some of the routers.

Thanks for the great work with httprouter!

[julienschmidt]

Duplicate of #4