Correct Monero build script

coins/monero/build.rs

@@ -1,7 +1,7 @@
 use std::{
   io::Write,
   path::Path,
-  fs::{File, remove_file},
+  fs::{File, DirBuilder, remove_file},
 };
 
 use dalek_ff_group::EdwardsPoint;
@@ -33,6 +33,7 @@ fn generators(prefix: &'static str, path: &str) {
   let mut H_str = "".to_string();
   serialize(&mut H_str, &generators.H);
 
+  DirBuilder::new().recursive(true).create(".generators").unwrap();
   let path = Path::new(".generators").join(path);
   let _ = remove_file(&path);
   File::create(&path)