Rspec inaccurately reports test loading time as including stack build time

[cwjohnston]

At the end of a validation run Rspec reports how long it took to run the tests:

 Finished in 2.52 seconds (files took 36 minutes 45 seconds to load)

In this case, validation occurring subsequent to running sfn create, Rspec reports that it took 36 minutes 45 seconds to load test files from disk. In reality this is how long it took to build the stacks leading up to this validation execution.