Fix typo in learner analytics developer message

analytics_data_api/v0/exceptions.py

@@ -41,7 +41,7 @@ class LearnerEngagementTimelineNotFoundError(BaseError):
 
     @property
     def message_template(self):
-        return 'Learner {username} engagmeent timeline not found for course {course_id}.'
+        return 'Learner {username} engagement timeline not found for course {course_id}.'
 
 
 class CourseNotSpecifiedError(BaseError):

analytics_data_api/v0/tests/views/test_engagement_timelines.py

@@ -116,7 +116,7 @@ class EngagementTimelineTests(DemoCourseMixin, VerifyCourseIdMixin, TestCaseWith
         self.assertEquals(response.status_code, status.HTTP_404_NOT_FOUND)
         expected = {
             u"error_code": u"no_learner_engagement_timeline",
-            u"developer_message": u"Learner {} engagmeent timeline not found for course {}.".format(
+            u"developer_message": u"Learner {} engagement timeline not found for course {}.".format(
                 self.DEFAULT_USERNAME, self.course_id)
         }
         self.assertDictEqual(json.loads(response.content), expected)