Use serve-static@1.7.1

serve-static 1.6.1 creates the following error when launching a dev server:

/home/spike/.nvm/v0.11.14/lib/node_modules/ionic/node_modules/serve-static/node_modules/send/node_modules/etag/index.js:55
    throw new TypeError('argument entity must be string, Buffer, or fs.Stats')
          ^
TypeError: argument entity must be string, Buffer, or fs.Stats
    at etag (/home/spike/.nvm/v0.11.14/lib/node_modules/ionic/node_modules/serve-static/node_modules/send/node_modules/etag/index.js:
55:11)
    at SendStream.setHeader (/home/spike/.nvm/v0.11.14/lib/node_modules/ionic/node_modules/serve-static/node_modules/send/index.js:72
4:15)
    at SendStream.send (/home/spike/.nvm/v0.11.14/lib/node_modules/ionic/node_modules/serve-static/node_modules/send/index.js:500:8)
    at onstat (/home/spike/.nvm/v0.11.14/lib/node_modules/ionic/node_modules/serve-static/node_modules/send/index.js:585:10)
    at Object.oncomplete (fs.js:93:15)
Fix for documentation about proxy settings
feat(lab): first version of Ionic Lab
Merge pull request #133 from sp4ke/master

Use serve-static@1.7.1
Merge branch 'master' into proxy-doc-update
Making the document easier to understand for proxying. Updated the options to be proxyUrl, as well as updating that value in serve.js
Fallback platform override
Update README.md
Merge pull request #148 from driftyco/proxy-doc-update

Fix for documentation about proxy settings
Bumping version to 1.2.9, adding myself as maintainer
Shrinkwrapped
Adding in the service/remove/add commands to assist in maintaining bower components
Adding in the service/remove/add commands to assist in maintaining bower components
Merge branch 'master' of github.com:driftyco/ionic-cli
Adding in the environment variable http_proxy for npm defaults, along with the PROXY env variable we suggested
Adding documenation to README about working around proxies, as well as adding in the additional http_proxy in lib/ionic.js
New serve
Nicer lab styles
vbump
Better lab