fix maildir expansion (#307)

* Applied shellexpand to maildir_dir

* change to account_config: applied shellexpand to maildir_dir

* rustfmt: removing required version, formatted project

* changing type of `maildir_dir` to `String` and adding shellexpand to
`maildir_dir`

src/config/account_config.rs

@@ -191,7 +191,7 @@ impl<'a> AccountConfig {
             }),
             DeserializedAccountConfig::Maildir(config) => {
                 BackendConfig::Maildir(MaildirBackendConfig {
-                    maildir_dir: config.maildir_dir.clone(),
+                    maildir_dir: shellexpand::full(&config.maildir_dir)?.to_string().into(),
                 })
             }
         };

src/config/deserialized_account_config.rs

@@ -121,4 +121,4 @@ make_account_config!(
     imap_passwd_cmd: String
 );
 
-make_account_config!(DeserializedMaildirAccountConfig, maildir_dir: PathBuf);
+make_account_config!(DeserializedMaildirAccountConfig, maildir_dir: String);