Travis CI builds don't pass with master branch anymore

[jacksonllee]

Curiously, the master branch (updated about two months ago) has had the builds all passed, while the exact same code now apparently cannot pass the builds. The test failures are due to two estimator checks (autoencoder and MLP classifier) not passed. The environments (packages, etc.) should be identical between two months and this week, but maybe there's something we've overlooked.

I came across this while investigating why the builds didn't pass at #101.

[timball]

any updates on this? would really like to get that tensorflow security PR merged in.

#101

--timball

[salilgupta1]

Hey @timball I'll take a look at this issue.

[mheilman]

#103 fixed the build, but I think we should leave this open since I fixed it by skipping part of scikit-learn's check_estimator function (see the PR for details). It'd be nice to solve that in a cleaner way eventually.