Bump rimraf from 2.6.2 to 2.6.3 (#10880)

Bumps [rimraf](https://github.com/isaacs/rimraf) from 2.6.2 to 2.6.3.
- [Release notes](https://github.com/isaacs/rimraf/releases)
- [Commits](https://github.com/isaacs/rimraf/compare/v2.6.2...v2.6.3)

package.json

@@ -149,7 +149,7 @@
     "rellax": "^1.7.1",
     "requestidlecallback": "^0.3.0",
     "reselect": "^4.0.0",
-    "rimraf": "^2.6.1",
+    "rimraf": "^2.6.3",
     "sass": "^1.17.2",
     "sass-loader": "^7.0.3",
     "stringz": "^1.0.0",