Use shx so that the npm scripts work everywhere the same.

package.json

@@ -18,11 +18,11 @@
   ],
   "scripts": {
     "change-version": "node grunt/change-version.js",
-    "shrinkwrap": "npm shrinkwrap --dev && mv ./npm-shrinkwrap.json ./grunt/npm-shrinkwrap.json",
     "eslint": "eslint --config js/.eslintrc.json js/src",
     "jscs": "jscs --config=js/.jscsrc js/src js/tests/unit docs/assets/js/src docs/assets/js/ie*.js grunt Gruntfile.js",
     "postcss": "postcss --config grunt/postcss.js --replace dist/css/*.css",
     "postcss-docs": "postcss --config grunt/postcss.js --no-map --replace docs/assets/css/docs.min.css && postcss --config grunt/postcss.js --no-map --replace docs/examples/**/*.css",
+    "shrinkwrap": "npm shrinkwrap --dev && shx mv ./npm-shrinkwrap.json ./grunt/npm-shrinkwrap.json",
     "test": "npm run eslint && npm run jscs && grunt test"
   },
   "style": "dist/css/bootstrap.css",
@@ -70,6 +70,7 @@
     "postcss-cli": "^2.5.2",
     "postcss-flexbugs-fixes": "^2.0.0",
     "shelljs": "^0.7.0",
+    "shx": "^0.1.2",
     "time-grunt": "^1.2.1"
   },
   "engines": {