Implemented deleting games as admin.

gamenight-database/src/game.rs

@@ -35,3 +35,10 @@ pub fn rename_game(
         .set(game::name.eq(&name))
         .execute(conn)?)
 }
+
+pub fn remove_game(
+    conn: &mut DbConnection,
+    id: Uuid,
+) -> Result<usize, DatabaseError> {
+    Ok(diesel::delete(game::table.filter(game::id.eq(id))).execute(conn)?)
+}