Add short description to course object in program response

LEARNER-1887

course_discovery/apps/api/serializers.py

@@ -535,7 +535,7 @@ class MinimalCourseSerializer(TimestampModelSerializer):
 
     class Meta:
         model = Course
-        fields = ('key', 'uuid', 'title', 'course_runs', 'owners', 'image',)
+        fields = ('key', 'uuid', 'title', 'course_runs', 'owners', 'image', 'short_description',)
 
 
 class CourseSerializer(MinimalCourseSerializer):

course_discovery/apps/api/tests/test_serializers.py

@@ -109,6 +109,7 @@ class MinimalCourseSerializerTests(TestCase):
             'course_runs': MinimalCourseRunSerializer(course.course_runs, many=True, context=context).data,
             'owners': MinimalOrganizationSerializer(course.authoring_organizations, many=True, context=context).data,
             'image': ImageField().to_representation(course.card_image_url),
+            'short_description': course.short_description
         }
 
     def test_data(self):