dataframes

sin, cos, etc.

In rust this is not needed as we can easily call apply(_cast)

Describe the bug
pa.errors.SchemaErrors.failure_cases only returns the first 10 failure_cases

• I have checked that this issue has not already been reported.
• I have confirmed this bug exists on the latest version of pandera. 0.6.5
• (optional) I have confirmed this bug exists on the master branch of pandera.

Note: Please read [this guide](https://matthewrocklin.c

I'm using black and isort for other projects (see e.g. https://github.com/hyperopt/hyperopt/pull/748/files) and find them quite useful to have more consistent codebase. I think you should drop python3.5 support though, as black is python3.6+. Is this something you would be open to consider?

Point in time+search_after is more memory efficient however requires a sort option to always be present. Luckily we can add sort: _doc as a good default.

Code coverage should be added to the Travis config (perhaps the cabal file and/or the stack options need to be changed in order to account for hpc coverage generation); currently in Travis there is only a project key.
This tool uploads hpc coverage reports to codecov.io .

Add a few useful date/time types from time (https://hackage.haskell.org/package/time) , e.g.

• POSIXTime
• Date
  etc.

A checklist for where to add things :

• prim constructors go in here : https://github.com/ocramz/heidi/blob/master/src/Data/Generics/Encode/Internal/Prim.hs#L25
• Heidi instances go here : https://github.com/ocramz/heidi/blob/master/src/Data/Generics