add updateRepos function

update user's starred repos

require db module
add db saveRepos and getUserStarred function
`/repo` api return db data. `/updateRepos` api return github api data

req.session.userId use to get user's repos
req.session.updated use to fetch github data only once
ngResource Repo add updateRepos method
GitHubApi debug mode turn off
add module in util.coffee
getAllStarredRepos add logger