added endpoints for changing password and username

src/services/user.js

@@ -31,6 +31,14 @@ class UserService {
         if (await (this.isInGroup(userId, groupId))) throw new customError(`joinGroup user already in group`, responseCodes.responses.user.already_in_group);
         await db.query("UPDATE Users SET groups = array_append(groups, $1::integer) WHERE ID = $2", [groupId, userId]);
     }
+
+    async changeUsername(userId, username) {
+        await db.query("UPDATE users SET username = $1 WHERE id = $2", [username, userId]).catch(e => errorHandler(e, "user"));
+    }
+
+    async changePassword(userId, password) {
+        await db.query("UPDATE users SET password = $1 WHERE id = $2", [bcrypt.hashSync(password, 12), userId])
+    }
 }
 
 export default new UserService();