Update GridsearchCV and initial microstructures
Update GridsearchCV and initial microstructures

Address #137 and #132

Update the example to work with the new dimension requirements for
gridsearchCV in sklearn. This change should have been completed with
pull request #134

The initial validation microstructures were changed to be generated
from a normal distribution to better reflect the physical process.

davidbrough1/pymks,davidbrough1/pymks,fredhohman/pymks,awhite40/pymks,XinyiGong/pymks