Install complete openssl on windows

tests/transport_file.rs

@@ -1,12 +1,14 @@
 extern crate lettre;
 
+use std::env::temp_dir;
+
 use lettre::transport::file::FileEmailTransport;
 use lettre::transport::EmailTransport;
 use lettre::email::EmailBuilder;
 
 #[test]
 fn file_transport() {
-    let mut sender = FileEmailTransport::new("/tmp/");
+    let mut sender = FileEmailTransport::new(temp_dir());
     let email = EmailBuilder::new()
                     .to("root@localhost")
                     .from("user@localhost")
@@ -16,4 +18,7 @@ fn file_transport() {
                     .unwrap();
     let result = sender.send(email);
     assert!(result.is_ok());
+
+    message_id = email.message_id();
+
 }