Fix platform specific os/process build

runtime/process/os/os_windows.go

@@ -10,9 +10,6 @@ import (
 	"github.com/micro/go-micro/runtime/process"
 )
 
-type Process struct {
-}
-
 func (p *Process) Exec(exe *process.Executable) error {
 	cmd := exec.Command(exe.Package.Path)
 	return cmd.Run()
@@ -90,7 +87,3 @@ func (p *Process) Wait(pid *process.PID) error {
 
 	return fmt.Errorf(ps.String())
 }
-
-func NewProcess(opts ...process.Option) process.Process {
-	return &Process{}
-}