Implement __str__ for Cohort model

[renzon]

it must return cohort´s name

[RamiroAlvaro]

Cohort model has no name attribute

class Cohort(models.Model):
    title = models.CharField(max_length=50)
    slug = models.SlugField()
    image = models.ImageField(upload_to='cohorts/')
    quote = models.TextField()
    mail_list = models.URLField()
    forum_post = models.URLField()
    start = models.DateField()
    end = models.DateField()
    students = models.ManyToManyField(get_user_model(), through='CohortStudent')

it must return cohort´s title ?

    def __str__(self):
        return self.title

[renzon]

Please include the prefix "Turma: <title>"