Added LoginUserRepository to get login_users.

backend/src/typeorm/repository/LoginUser.ts

@@ -0,0 +1,11 @@
+import { EntityRepository, Repository } from 'typeorm'
+import { LoginUser } from '@entity/LoginUser'
+
+@EntityRepository(LoginUser)
+export class LoginUserRepository extends Repository<LoginUser> {
+  async findByEmail(email: string): Promise<LoginUser> {
+    return this.createQueryBuilder('loginUser')
+      .where('loginUser.email = :email', { email })
+      .getOneOrFail()
+  }
+}