Fix tests

src/testhelpers.rs

@@ -20,7 +20,7 @@ impl TestUserDao {
 }
 
 impl UserDao for TestUserDao {
-    fn create_user(&self, username: &str, password: &str) -> Option<User> {
+    fn create_user(&mut self, username: &str, password: &str) -> Option<User> {
         let u = User {
             id: (self.user_map.borrow().len() + 1) as i32,
             username: username.to_string(),
@@ -32,7 +32,7 @@ impl UserDao for TestUserDao {
         Some(u)
     }
 
-    fn get_user(&self, user: &str, pass: &str) -> Option<User> {
+    fn get_user(&mut self, user: &str, pass: &str) -> Option<User> {
         match self
             .user_map
             .borrow()
@@ -47,7 +47,7 @@ impl UserDao for TestUserDao {
         }
     }
 
-    fn user_exists(&self, user: &str) -> bool {
+    fn user_exists(&mut self, user: &str) -> bool {
         self.user_map
             .borrow()
             .iter()