Test modified pypi settings

This is a test release to verify the new pypi settings

Add support for survival-type formulas

New features:

1. Allow prep_pp_survival_data to receive pp_data as a dataframe, rather than force the user to use internal functions provided by a list of columns - issue #57.
2. Support for detailing parameters to SurvivalStanData within a patsy formula, rather than passing as parameters. This is optional, but will make certain features (like supporting competing risks or joint models - issue #36 ) down the line cleaner. Is also a prerequisite for allowing more flexible spec of varying-coefs - issue #47.
3. Add iter column to time_betas extract - issue #73

Variety of bug fixes:

1. Fixed incompatibility with pandas >= 0.23.4 (pandas-dev/pandas#23733) #76
2. Fixed log_t_dur incorrectly specific #71
3. Fixed #78

Fix errors installing from pypi

Fix errors installing from pypi

Minor change to manifest.in

Merge pull request #37 from hammerlab/jburos-patch-1

Update MANIFEST.in