move fields to public to support the new binary IO
move Relation to hpp
include the call to parallel io
i thought i changed this
Merge branch 'master' into bmyerz-grappa-improves
Merge branch 'bmyerz-grappa-improves' of github.com:uwescience/datalogcompiler into bmyerz-grappa-improves
flake8
Merge pull request #193 from uwescience/bmyerz-grappa-improves

Grappalang: Parallel File IO