benchmarks: update lua scripts to send working requests

[Raynos]

The benchmarks lua's were stale compared to the validation
that we do.

When we run the benchmarks they "work", aka wrk is able
to send requests, however the benchmarks we run do
not return 2xx and wrk mentions this but wrk is happy
about any response.

r: @uber/zanzibar-team

[coveralls]

Coverage remained the same at 73.784% when pulling be24dcc on fix-benchmarks into f7255d5 on master.