Add message for setting course goal.

LEARNER-2307

lms/djangoapps/course_goals/models.py

@@ -0,0 +1,35 @@
+"""
+Course Goals Models
+"""
+from django.contrib.auth.models import User
+from django.db import models
+from openedx.core.djangoapps.xmodule_django.models import CourseKeyField
+
+
+class CourseGoal(models.Model):
+    """
+    Represents a course goal set by a user on the course home page.
+
+    The goal_key represents the goal key that maps to a translated
+    string through using the CourseGoalOption class.
+    """
+    GOAL_KEY_CHOICES = (
+        ('certify', 'Earn a certificate.'),
+        ('complete', 'Complete the course.'),
+        ('explore', 'Explore the course.'),
+        ('unsure', 'Not sure yet.'),
+    )
+
+    user = models.ForeignKey(User, blank=False)
+    course_key = CourseKeyField(max_length=255, db_index=True)
+    goal_key = models.CharField(max_length=100, choices=GOAL_KEY_CHOICES, default='unsure')
+
+    def __unicode__(self):
+        return 'CourseGoal: {user} set goal to {goal} for course {course}'.format(
+            user=self.user.username,
+            course=self.course_key,
+            goal_key=self.goal_key,
+        )
+
+    class Meta:
+        unique_together = ("user", "course_key")