Fix unparseable package.json

npm install will fail to do anything because package.json is not valid json - there is a trailing comma in the devDependencies node. See below for error.

$ npm install
npm ERR! install Couldn't read dependencies
npm ERR! Failed to parse json
npm ERR! Unexpected token }
npm ERR! File: D:\nginx\html\dash.js\package.json
npm ERR! Failed to parse package.json data.
npm ERR! package.json must be actual JSON, not just JavaScript.
npm ERR!
npm ERR! This is not a bug in npm.
npm ERR! Tell the package author to fix their package.json file. JSON.parse

npm ERR! System Windows_NT 6.1.7601
npm ERR! command "c:\\Program Files\\nodejs\\node.exe" "c:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install"
npm ERR! cwd D:\nginx\html\dash.js
npm ERR! node -v v0.10.25
npm ERR! npm -v 1.3.24
npm ERR! file D:\work\dash.js\package.json
npm ERR! code EJSONPARSE
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR!     D:\nginx\html\dash.js\npm-debug.log
npm ERR! not ok code 0