Creating Performance Testing Suite

[houllette]

It would be helpful to build a performance testing suite for Sobelow to A) establish a baseline for performance B) monitor how feature changes affect scanning performance.

We would most likely want to use the Benchee library in our suite and we could establish a habit of writing out the performance results of a version to the Sobelow repo itself as they are released to measure against for subsequent versions (i.e. write out results of benchee suite running on Sobelow v.0.X.0 so we could later compare it to v0.Y.0)