go dep inj via interface and constructor

athea.go

package athena

import (
	accountant "codeship-accountant",
	janus "codeship-janus",
	ares "ares-api"
)

func main() {
	// codeship accountant implements accountant interface
	accountant := accountant.New()
	// codeship janus implements janus interface
	janus := janus.New()
	// this is a general purpose ares api for stuff or whatever
	ares := ares.New()

	athena.New(accountant, janus, ares)
}