remove graceful-fs patch

This was originally reported in
#254 as a fix
for a Jest error, but seems no longer necessary.

Author: nicolodavis

package-lock.json

@@ -100,7 +100,6 @@
     "firebase": "^7.5.2",
     "firebase-admin": "^8.5.0",
     "firebase-mock": "^2.2.10",
-    "graceful-fs": "https://github.com/mekwall/node-graceful-fs.git#patch-1",
     "husky": "^1.3.1",
     "identity-obj-proxy": "^3.0.0",
     "jest": "^24.0.0",