fixing the tests I broke late last night
move this back to 10e-4
fix this test to use new interpretation
Merge pull request #113 from CamDavidsonPilon/raise-value-error-over-assert

fixing the tests I broke late last night
Make lifelines work in pure python mode

Added a pure python version of concordance index,
as a fallback option, for developers without access
to a proper compiler (Windows people). This allows for
easier contribution to the library, while still allowing
us to maintain the higher speed for users who install from
pypi.

The setup script will now try to compile the extensions, and if
it fails, it will do it again with just the python source.

Signed-off-by: Jonas Kalderstam <jonas@kalderstam.se>
Added test for python version of cindex

Signed-off-by: Jonas Kalderstam <jonas@kalderstam.se>