DOC: update scipy version from 0.7 to 0.9.0
Merge pull request #1160 from argriffing/update-scipy-090

DOC: update scipy version from 0.7 to 0.9.0
BUG: Replaced log(det(x)) with slogdet(x) to avoid numerical problems in loglike
ENH: Many typos fixed
ENH: Better PEP8 compliance in a few places