DOC: PolynomialFeatures narrative doc
DOC: fix auto-links
DOC: fix Polynomial Regression docs
ENH: Raise explicitly on non-unique vocab.
remove EllipticEnvelop deprecation
Merge pull request #2653 from jaquesgrobler/remove_ellipticenvelope_deprecation

remove EllipticEnvelop deprecation
Remove deprecated zero_one and zero_one_score
Merge pull request #2649 from jakevdp/polynomial_doc

DOC: Polynomial regression narrative doc
flake8
Merge pull request #2654 from arjoly/metrics-0.15

[MRG] Remove deprecated zero_one and zero_one_score
DOC: fix test failure in linear model
Website: add spotify testimonials
Merge pull request #2651 from amueller/spotify_testimonial

MRG Website: add spotify testimonials
FIX silence numpy 1.8 warning for using non integer
Merge pull request #2656 from arjoly/np1.8-warnings

[MRG] FIX silence numpy 1.8 warning for using non integer
SPD: reuse variable in GaussianNB for speedup
Merge pull request #2659 from jakevdp/gaussiannb_speedup

SPD: reuse variable in GaussianNB for speedup