Add golint to test (#255)

* Add a new lint rule to the Makefile

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

* Fix linter errors

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

* Allow replacing the default apt mirror

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

supervisor/machine.go

@@ -4,11 +4,14 @@ package supervisor
 
 import "github.com/cloudfoundry/gosigar"
 
+// Machine holds the current machine cpu count and ram size
 type Machine struct {
 	Cpus   int
 	Memory int64
 }
 
+// CollectMachineInformation returns information regarding the current
+// machine (e.g. CPU count, RAM amount)
 func CollectMachineInformation() (Machine, error) {
 	m := Machine{}
 	cpu := sigar.CpuList{}