Fix the SQlite build

plume-models/src/post_authors.rs

@@ -4,7 +4,7 @@ use posts::Post;
 use users::User;
 use schema::post_authors;
 
-#[derive(Queryable, Identifiable, Associations)]
+#[derive(Clone, Queryable, Identifiable, Associations)]
 #[belongs_to(Post)]
 #[belongs_to(User, foreign_key = "author_id")]
 pub struct PostAuthor {