do not include workflow jobs for reaping

* Workflow jobs are virtual jobs that don't actually run. Thus they
won't have a celery id and aren't candidates for the generic reaping.
* Better error logging when Instance not found in reaping code.

awx/main/tests/functional/task_management/test_scheduler.py

@@ -9,6 +9,7 @@ from awx.main.scheduler import TaskManager
 from awx.main.models import (
     Job,
     Instance,
+    WorkflowJob,
 )
 
 
@@ -250,7 +251,9 @@ class TestReaper():
 
         j11 = Job.objects.create(status='running', celery_task_id='host4_j11', execution_node='host4_offline')
 
-        js = [j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11]
+        j12 = WorkflowJob.objects.create(status='running', celery_task_id='workflow_job', execution_node='host1')
+
+        js = [j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12]
         for j in js:
             j.save = mocker.Mock(wraps=j.save)
             j.websocket_emit_status = mocker.Mock()
@@ -263,7 +266,7 @@ class TestReaper():
     @pytest.fixture
     def running_tasks(self, all_jobs):
         return {
-            'host1': all_jobs[2:5],
+            'host1': all_jobs[2:5] + [all_jobs[11]],
             'host2': all_jobs[5:8],
             'host3_split': all_jobs[8:10],
             'host4_offline': [all_jobs[10]],
@@ -331,3 +334,5 @@ class TestReaper():
         assert all_jobs[9] in execution_nodes_jobs['host3_split']
 
         assert all_jobs[10] in execution_nodes_jobs['host4_offline']
+
+        assert all_jobs[11] not in execution_nodes_jobs['host1']

awx/main/tests/unit/test_task_manager.py

@@ -31,8 +31,8 @@ class TestCleanupInconsistentCeleryTasks():
 
         assert "mocked" in str(excinfo.value)
         logger_mock.error.assert_called_once_with("Execution node Instance host1 not found in database. "
-                                                  "The node is currently executing jobs ['None-2-new', "
-                                                  "'None-3-new']")
+                                                  "The node is currently executing jobs ['job 2 (new)', "
+                                                  "'job 3 (new)']")
 
     @mock.patch.object(cache, 'get', return_value=None)
     @mock.patch.object(TaskManager, 'get_active_tasks', return_value=([], {'host1': []}))