use standard library in sesh to make directories instead of mkdir program

sesh/main.go

@@ -55,7 +55,6 @@ type Config map[string][]Window
 
 const (
 	tmux  = "tmux"
-	mkdir = "mkdir"
 )
 
 func main() {
@@ -64,11 +63,6 @@ func main() {
 		panic(err)
 	}
 
-	_, err = exec.LookPath(mkdir)
-	if err != nil {
-		panic(err)
-	}
-
 	homeDir, err := os.UserHomeDir()
 	if err != nil {
 		panic(err)
@@ -161,8 +155,7 @@ func main() {
 			return
 		}
 		for _, window := range sesh {
-			// TODO: use go stdandard library instead
-			exec.Command(mkdir, "-p", window.ExpandedPath()).Run()
+			_ = os.MkdirAll(window.ExpandedPath(), 0775);
 		}
 		for _, window := range sesh {
 			NewWindowInSession(seshName, window)