Simplify docs npm script

Author: lutovich

package.json

@@ -14,7 +14,7 @@
     "start-neo4j": "gulp start-neo4j",
     "stop-neo4j": "gulp stop-neo4j",
     "run-tck": "gulp run-tck",
-    "docs": "node_modules/.bin/esdoc -c esdoc.json"
+    "docs": "esdoc -c esdoc.json"
   },
   "main": "lib/index.js",
   "devDependencies": {