remove realpath since it's not needed by better errors anymore.

Author: jordwalke

package.json

@@ -49,7 +49,6 @@
     "reason": "^ 1.6.0",
     "@opam-alpha/ocaml": "4.2.3",
     "dependency-env": "^0.1.1",
-    "fastrealpath": "^0.1.0",
     "nopam": "^0.1.0"
   },
   "engines": {