Signing activities

I hope it works correctly…

Fixes #6

src/routes/posts.rs

@@ -56,7 +56,7 @@ fn create(blog_name: String, data: Form<NewPostForm>, user: User, conn: DbConn)
     });
 
     let act = Create::new(&user, &post, &*conn);
-    broadcast(&*conn, act, user.get_followers(&*conn));
+    broadcast(&*conn, &user, act, user.get_followers(&*conn));
 
     Redirect::to(format!("/~/{}/{}", blog_name, slug).as_str())
 }

src/routes/user.rs

@@ -34,7 +34,7 @@ fn follow(name: String, conn: DbConn, user: User) -> Redirect {
         follower_id: user.id,
         following_id: target.id
     });
-    target.send_to_inbox(&*conn, activity::Follow::new(&user, &target, &*conn));
+    target.send_to_inbox(&*conn, &user, activity::Follow::new(&user, &target, &*conn));
     Redirect::to(format!("/@/{}", name).as_ref())
 }