fix(package): update documentation to version 4.0.0-rc.0

https://greenkeeper.io/

Author: greenkeeper[bot]

package.json

@@ -4,7 +4,7 @@
   "version": "3.2.0",
   "author": "Tom MacWright",
   "dependencies": {
-    "documentation": "4.0.0-beta.18",
+    "documentation": "4.0.0-rc.0",
     "through2": "^2.0.1",
     "vinyl": "^2.0.0"
   },