clean-css: add sourcemaps support (#731) (13947da) make the $1 work for non .js files (#733) (03d0cbd) uglifyjs: use filename instead of url (#738) (b913733) drop support of node 6 (#739) (96e91b0) html-minifier: use public folder with $1 (#746) (f638e47 f55adec 0b5dc89) Bump packages