whereami 1.0 (new formula)

whereami is a command line tool to obtain your location (as a latitude, longitude pair)
I'm not sure how to declare a dependency on swift (in addition to making it depend on Mac OS X 10.0), or even if it is needed; suggestions are welcome
Probably worth making this a `depends_on :xcode => ["6.1.1", :build]` instead (like `carthage.rb` which also uses Swift)