added imports on slides css for heroku precompile
added imports on slides css for heroku precompile

NYPL/building-inspector,nypl-spacetime/building-inspector,timwaters/building-inspector,NYPL/building-inspector,NYPL/building-inspector,timwaters/building-inspector,nypl-spacetime/building-inspector,nypl-spacetime/building-inspector,timwaters/building-inspector,timwaters/building-inspector,NYPL/building-inspector,nypl-spacetime/building-inspector,nypl-spacetime/building-inspector,NYPL/building-inspector