add tests for dc.transition parameters
add tests for dc.transition parameters

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