Speed up Travis with Conda

By using conda packages for the SciPy stack we avoid the need to compile
numpy and the rest from scratch each time. This should increase the
speed of the builds dramatically.

Signed-off-by: Jonas Kalderstam <jonas@kalderstam.se>
Merge pull request #61 from spacecowboy/travis_conda

Speed up Travis with Conda
adding parts of cox regression
commiting before restart
tests pass
adding confidence intervals
removing scratch efron file, moving baldwin file for later inclusion
fixing test; cf.hazards_ are now dataframe
bump version
removing asserts
tf
adding rossi data, tests + more cox features
testing cox predictions
pepping the whole thing
add cox to rtfd and __init__.py
add python3 printing to stats.py
Merge pull request #62 from CamDavidsonPilon/cox-regression

Cox Regression