Fix windows postinstall (#28)

* fix postinstall for windows
* version bump
diff --git a/client/bin/postinstall b/client/bin/postinstall
index 507d18a..1673157 100755
--- a/client/bin/postinstall
+++ b/client/bin/postinstall
@@ -1,5 +1,3 @@
-#!/usr/bin/env node
-
 /**
   * Copyright 2015-2016 IBM Corporation
   *
diff --git a/client/package.json b/client/package.json
index f72468d..b53d53e 100644
--- a/client/package.json
+++ b/client/package.json
@@ -1,6 +1,6 @@
 {
   "name": "openwhisk-debugger",
-  "version": "0.0.23",
+  "version": "0.0.24",
   "description": "A debugger for OpenWhisk",
   "repository": {
     "type": "git",
@@ -12,7 +12,7 @@
   },
   "scripts": {
     "prepublish": "./bin/prepublish",
-    "postinstall": "./bin/postinstall",
+    "postinstall": "node ./bin/postinstall",
     "test": "./node_modules/.bin/jshint wskdb.js lib/*.js lib/commands/*.js && ./util/scanCode.sh && ava --verbose --serial"
   },
   "bugs": {