Optimize parameter ranges for randomized grid search

[praftery]

This relates to the randomized grid search to find the optimal set of parameters for each regressor (or at least, a reasonably good set anyway). The bounds on possible parameter values may be too broad, or too narrow, or may not really matter too much at all for our application (!), so it's probably worth looking into.

We could use the EnerNOC data for testing this out:
http://www.datadrivenbuilding.org/100-EnerNOC-Commercial-Buildings
http://open.enernoc.com/data/

[praftery]

That EnerNOC site is down. Direct link to the 100 building data: https://open-enernoc-data.s3.amazonaws.com/anon/all-data.tar.gz