bench sinatra v1.4.5

This adds a sinatra app to bench against.  Notice only a slight
increase in req/s.  This is expected b/c the latest version of Deas
wraps and uses Sinatra under the covers.

This will be a reference for future Deas updates.

/cc @jcredding
rework the deas latest to deas v0.25.0

Wanna be explicit about version benchmarks.

/cc @jcredding
update README with Sinatra results

/cc @jcredding