Watcher: Added teardown sections to the REST tests

The tests have been failing because they haven't cleaned up the environment
after their run, leaving documents with watches behind.

This patch adds `teardown` sections which delete the documents
created by tests.

Related: elastic/elasticsearch#2648

Closes elastic/elasticsearch#2690

Original commit: elastic/x-pack-elasticsearch@e34e40d879

elasticsearch/x-pack/watcher/src/test/resources/rest-api-spec/test/xpack/watcher/get_watch/10_basic.yaml

@@ -1,9 +1,18 @@
 ---
-"Test get watch api":
+setup:
   - do:
       cluster.health:
           wait_for_status: yellow
 
+---
+teardown:
+  - do:
+      xpack.watcher.delete_watch:
+        id: "my_watch"
+        ignore: 404
+
+---
+"Test get watch api":
   - do:
       xpack.watcher.put_watch:
         id: "my_watch"

elasticsearch/x-pack/watcher/src/test/resources/rest-api-spec/test/xpack/watcher/getting_started/10_monitor_cluster_health.yaml

@@ -1,10 +1,18 @@
 ---
-"Getting started - Monitor cluster health":
+setup:
   - do:
       cluster.health:
-          wait_for_status: yellow
+        wait_for_status: yellow
 
+---
+teardown:
+  - do:
+      xpack.watcher.delete_watch:
+        id: "cluster_health_watch"
+        ignore: 404
 
+---
+"Getting started - Monitor cluster health":
   - do:
       xpack.watcher.stats: {}
   - match: { "watcher_state": "started" }

elasticsearch/x-pack/watcher/src/test/resources/rest-api-spec/test/xpack/watcher/put_watch/20_put_watch_with_throttle_period.yaml

@@ -1,9 +1,18 @@
 ---
-"Test put watch api with watch level throttle":
+setup:
   - do:
       cluster.health:
-          wait_for_status: yellow
+        wait_for_status: yellow
 
+---
+teardown:
+  - do:
+      xpack.watcher.delete_watch:
+        id: "my_watch1"
+        ignore: 404
+
+---
+"Test put watch api with watch level throttle":
   - do:
       xpack.watcher.put_watch:
         id: "my_watch1"

elasticsearch/x-pack/watcher/src/test/resources/rest-api-spec/test/xpack/watcher/put_watch/30_put_watch_with_action_throttle_period.yaml

@@ -1,9 +1,18 @@
 ---
-"Test put watch api with action level throttle period":
+setup:
   - do:
       cluster.health:
-          wait_for_status: yellow
+        wait_for_status: yellow
 
+---
+teardown:
+  - do:
+      xpack.watcher.delete_watch:
+        id: "my_watch1"
+        ignore: 404
+
+---
+"Test put watch api with action level throttle period":
   - do:
       xpack.watcher.put_watch:
         id: "my_watch1"

elasticsearch/x-pack/watcher/src/test/resources/rest-api-spec/test/xpack/watcher/put_watch/40_put_watch_as_inactive.yaml

@@ -1,15 +1,24 @@
 ---
-"Test put inactive watch":
+setup:
   - do:
       cluster.health:
           wait_for_status: yellow
 
+---
+teardown:
+  - do:
+      xpack.watcher.delete_watch:
+        id: "my_watch"
+        ignore: 404
+
+---
+"Test put inactive watch":
   - do:
       xpack.watcher.put_watch:
         id: "my_watch"
         master_timeout: "40s"
         active: false
-        body:  > 
+        body:  >
           {
             "trigger": {
               "schedule": {