Move errors to commander.go

commander.go

@@ -1,11 +1,21 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"os/exec"
 	"strings"
 )
 
+type ShellError struct {
+	Command string
+	Err     error
+}
+
+func (e *ShellError) Error() string {
+	return fmt.Sprintf("Cannot run %q. Error %v", e.Command, e.Err)
+}
+
 type Commander interface {
 	Exec(cmd *exec.Cmd) (string, error)
 	ExecSilently(cmd *exec.Cmd) error

errors.go

@@ -1,12 +0,0 @@
-package main
-
-import "fmt"
-
-type ShellError struct {
-	Command string
-	Err     error
-}
-
-func (e *ShellError) Error() string {
-	return fmt.Sprintf("Cannot run %q. Error %v", e.Command, e.Err)
-}