Install the deps with error '404 Not Found: serve@^6.4.8'

[Tiny Chou]

tinys-MacBook-Pro:rollup-starter-app tinychou$ npm i
WARN tar ENOENT: no such file or directory, open '/Users/tinychou/Public/git_repo/rollup-starter-app/node_modules/.staging/is-extglob-3003c40a/package.json'
WARN tar ENOENT: no such file or directory, open '/Users/tinychou/Public/git_repo/rollup-starter-app/node_modules/.staging/is-extglob-3003c40a/README.md'
WARN tar ENOENT: no such file or directory, open '/Users/tinychou/Public/git_repo/rollup-starter-app/node_modules/.staging/is-extglob-3003c40a/LICENSE'
WARN tar ENOENT: no such file or directory, open '/Users/tinychou/Public/git_repo/rollup-starter-app/node_modules/.staging/is-extglob-3003c40a/index.js'
npm WARN rollup-starter-app@ No repository field.
npm WARN rollup-starter-app@ No license field.

npm ERR! code E404
npm ERR! 404 Not Found: serve@^6.4.8

npm ERR! A complete log of this run can be found in:
npm ERR! /Users/tinychou/.npm/_logs/2018-06-02T01_26_57_948Z-debug.log

[Tiny Chou]

when I remove the serve@6.4.8 in package.json and try npm i serve@latest
serve@7.2.0 installed and no errors any more.

[Tiny Chou]

by the way, Module serve should be in the devDependencies and not in dependencies. This just my private thoughts. :)

[Jon Swenson]

This PR updates dependencies and works fine. #10