Add quotation marks

Update constant to "constant",so it will work well.

Change-Id: I62aa93892fc53e78da52b1d391aa2e58022b449a

certification/openstack/macro/macro.yaml

@@ -34,7 +34,7 @@
 {%- endmacro %}
 
 {%- macro constant_runner(concurrency=1, times=1, is_smoke=True) %}
-        type: constant
+        type: "constant"
   {%- if is_smoke %}
         concurrency: 1
         times: 1

samples/tasks/scenarios/nova/boot-and-block-migrate.yaml

@@ -8,7 +8,7 @@ NovaServers.boot_and_live_migrate_server:
       name: "^cirros.*uec$"
     block_migration: true
   runner:
-    type: constant
+    type: "constant"
     times: 10
     concurrency: 2
   context:

samples/tasks/scenarios/nova/boot-and-live-migrate.yaml

@@ -8,7 +8,7 @@ NovaServers.boot_and_live_migrate_server:
       name: "^cirros.*uec$"
     block_migration: false
   runner:
-    type: constant
+    type: "constant"
     times: 10
     concurrency: 2
   context:

samples/tasks/scenarios/nova/boot-and-migrate.yaml

@@ -7,7 +7,7 @@ NovaServers.boot_and_migrate_server:
     image:
       name: "^cirros.*uec$"
   runner:
-    type: constant
+    type: "constant"
     times: 10
     concurrency: 2
   context:

samples/tasks/scenarios/nova/boot-and-rebuild.yaml

@@ -9,7 +9,7 @@ NovaServers.boot_and_rebuild_server:
     to_image:
       name: "^cirros.*uec$"
   runner:
-    type: constant
+    type: "constant"
     times: 5
     concurrency: 2
   context:

samples/tasks/scenarios/nova/boot-server-attach-created-volume-and-live-migrate.yaml

@@ -9,7 +9,7 @@ NovaServers.boot_server_attach_created_volume_and_live_migrate:
     size: 10
     block_migration: false
   runner:
-    type: constant
+    type: "constant"
     times: 5
     concurrency: 1
   context:

samples/tasks/scenarios/nova/boot-server-from-volume-and-live-migrate.yaml

@@ -10,7 +10,7 @@ NovaServers.boot_server_from_volume_and_live_migrate:
     volume_size: 10
     force_delete: false
   runner:
-    type: constant
+    type: "constant"
     times: 10
     concurrency: 2
   context:

samples/tasks/scenarios/vm/boot_runcommand_delete_custom_image.yaml

@@ -11,7 +11,7 @@ VMTasks.boot_runcommand_delete_custom_image:
       concurrency: 1
       timeout: 3000
       times: 1
-      type: constant
+      type: "constant"
     context:
       image_command_customizer:
         command: