Support GitHub packages urls (golang, swift, ...)

[baruchiro]

There are some use cases to support Github repo analysis (by connecting it to its package, or by itself).

• Install NPM package from Github: npm install git://github.com/user-c/dep-2#node0.8.0
• Go packages
• Swift
• Enhance package insights with repo insights.

Way to support:

• Support the go get command, the Github repo there is for sure a Go package.
• Identify if a repo is a Go package
• Find links to Go packages
• Identify if a repo is a package in which language.