chore(package): update gulp-shell to version 0.7.1

Closes #114

Author: greenkeeper[bot]

package.json

@@ -76,7 +76,7 @@
     "gulp-notify": "^3.2.0",
     "gulp-nsp": "^3.0.0",
     "gulp-rename": "^1.2.2",
-    "gulp-shell": "^0.6.2",
+    "gulp-shell": "^0.7.1",
     "gulp-tar": "^2.1.0",
     "gulp-todo": "^6.0.0",
     "gulp-tslint": "^8.1.3",