Don't ignore options diff in synthetics resource (#707)

We ignore the diff completely when options_list is set, which sounds
like unwanted behavior.

Closes #697

* Add a test

* Update an existing test instead

datadog/resource_datadog_synthetics_test_.go

@@ -242,11 +242,6 @@ func syntheticsTestOptions() *schema.Schema {
 		ConflictsWith: []string{"options_list"},
 		Deprecated:    "This parameter is deprecated, please use `options_list`",
 		DiffSuppressFunc: func(key, old, new string, d *schema.ResourceData) bool {
-			// DiffSuppressFunc is useless if options_list exists
-			if _, isOptionsV2 := d.GetOk("options_list"); isOptionsV2 {
-				return isOptionsV2
-			}
-
 			if key == "options.follow_redirects" || key == "options.accept_self_signed" || key == "options.allow_insecure" {
 				// TF nested schemas is limited to string values only
 				// follow_redirects, accept_self_signed and allow_insecure being booleans in Datadog json api

datadog/resource_datadog_synthetics_test_test.go

@@ -399,6 +399,8 @@ func createSyntheticsAPITestStep(accProvider *schema.Provider, clock clockwork.F
 				"datadog_synthetics_test.foo", "options.min_location_failed", "1"),
 			resource.TestCheckResourceAttr(
 				"datadog_synthetics_test.foo", "options.retry_count", "1"),
+			resource.TestCheckResourceAttr(
+				"datadog_synthetics_test.foo", "options_list.#", "0"),
 			resource.TestCheckResourceAttr(
 				"datadog_synthetics_test.foo", "name", testName),
 			resource.TestCheckResourceAttr(
@@ -668,6 +670,8 @@ func updateSyntheticsAPITestStep(accProvider *schema.Provider, clock clockwork.F
 				"datadog_synthetics_test.foo", "options_list.0.retry.0.interval", "500"),
 			resource.TestCheckResourceAttr(
 				"datadog_synthetics_test.foo", "options_list.0.monitor_options.0.renotify_interval", "100"),
+			// Make sure the legacy attribute isn't set anymore
+			resource.TestCheckNoResourceAttr("datadog_synthetics_test.foo", "options.tick_every"),
 			resource.TestCheckResourceAttr(
 				"datadog_synthetics_test.foo", "name", testName),
 			resource.TestCheckResourceAttr(
@@ -1030,6 +1034,8 @@ func createSyntheticsTCPTestStep(accProvider *schema.Provider, clock clockwork.F
 				"datadog_synthetics_test.tcp", "locations.0", "aws:eu-central-1"),
 			resource.TestCheckResourceAttr(
 				"datadog_synthetics_test.tcp", "options_list.0.tick_every", "60"),
+			// Make sure the legacy attribute isn't set anymore
+			resource.TestCheckNoResourceAttr("datadog_synthetics_test.tcp", "options.tick_every"),
 			resource.TestCheckResourceAttr(
 				"datadog_synthetics_test.tcp", "name", testName),
 			resource.TestCheckResourceAttr(