chore(package): update gulp-htmlmin to version 3.0.0 (#1284)

https://greenkeeper.io/

package.json

@@ -35,7 +35,7 @@
     "gulp-css-url-adjuster": "^0.2.3",
     "gulp-eslint": "~3.0.1",
     "gulp-flatten": "~0.3.0",
-    "gulp-htmlmin": "~2.0.0",
+    "gulp-htmlmin": "~3.0.0",
     "gulp-if": "~2.0.1",
     "gulp-inject": "~4.1.0",
     "gulp-minify-css": "~1.2.4",