chore(dep): replace gulp-minify-css with gulp-cssnano for css minific…

…ation

gulp-minify-css has been deprecated in favor of gulp-cssnano.

package.json

@@ -48,10 +48,10 @@
 		"gulp-cachebust": "0.0.6",
 		"gulp-coffee": "2.3.1",
 		"gulp-concat": "2.6.0",
+		"gulp-cssnano": "2.1.0",
 		"gulp-if": "2.0.0",
 		"gulp-jsonminify": "1.0.0",
 		"gulp-less": "3.0.5",
-		"gulp-minify-css": "1.2.2",
 		"gulp-minify-html": "1.0.4",
 		"gulp-nodemon": "2.0.6",
 		"gulp-plumber": "1.0.1",

tasks/minify/minify-css.coffee

@@ -1,10 +1,10 @@
 module.exports = (config, gulp) ->
 	q           = require 'q'
-	minifyCss   = require 'gulp-minify-css'
+	minifyCss   = require 'gulp-cssnano'
 	promiseHelp = require "#{config.req.helpers}/promise"
 	minOpts =
-		advanced: false
-		processImport: false # inlining imports in inline-css-imports
+		save: true
+		normalizeUrl: false # build does this, see absolute-css-urls
 
 	runTask = (appOrRb) ->
 		defer = q.defer()