function createSession(agent, user) {
  return agent
    .post('/login')
    .send({
      username: user.username,
      password: user.password
    })
    .expect(200)
    .then(res => {
      const cookie = res
        .headers['set-cookie'][0]
        .split(',')
        .map(item => item.split(';')[0])

      agent.jar.setCookies(cookie);
    });
}