apparently the grunt file interface changed
apparently the grunt file interface changed

was getting:
Warning: Path must be a string. Received undefined

i can't find any reference to the `basepath` we were using before, guess
that was undocumented stuff that got removed. `cwd` does the same thing a
different way

ref: #1233

mtraynham/dc.js,aaronhoffman/dc.js,mtraynham/dc.js,TheDataShed/dc.js,aaronhoffman/dc.js,aaronhoffman/dc.js,mtraynham/dc.js,TheDataShed/dc.js,dc-js/dc.js,dc-js/dc.js,aaronhoffman/dc.js,TheDataShed/dc.js,aaronhoffman/dc.js,mtraynham/dc.js,TheDataShed/dc.js,mtraynham/dc.js,dc-js/dc.js,dc-js/dc.js,dc-js/dc.js,TheDataShed/dc.js