remove gulp-chell not need

Author: Scrum

package.json

@@ -35,7 +35,6 @@
     "gulp-postcss": "^6.0.0",
     "gulp-release-tasks": "0.0.3",
     "gulp-rename": "^1.2.2",
-    "gulp-shell": "^0.4.3",
     "postcss-at-rules-variables": "0.0.11",
     "postcss-banner": "^1.0.0",
     "postcss-calc": "^5.0.0",