it('it should signin a new user', (done) => {
      request(app)
      .post('/api/users/signin')
      .send({
        username: "Charles",
        password: "challenger",
      })
      .expect(200)
      .end((err, res) => {
        if (err) {
          return done(err);
        }

        done()
      });
    });

signin(req, res) {

    const username = req.body.username.toLowerCase().trim();
    // const email = req.body.email.trim();

    if(!username) {
      return res.status(401)
      .send(
        {status: false,
          message: "Username cannot be empty"
        });
    }
    else if (!req.body.password) {
      return res.status(401)
      .send({
        status: false,
        message: "Password field cannot be empty"
        });
    }
    return User.findOne({
      where: {
        username,
      }
    })
    .then((user) =>{

      if(!user) {
        return res.status(401).send({message: "User is not registered"})
      }
      else if(!user.validPassword(req.body.password)){
        return res.status(401)
        .send({
          message: "The password is incorrect"
        })
      }
      const token = user.generateAuthToken();
      res.header('x-auth', token).status(200).send({
      statusCode: 200,
      message: `Welcome back, ${user.username}`,
      user
    });
    })
    .catch(error => {return res.status(400).send(error)})
  },