Remove collate filter from PhraseSuggester

The `filter` has been removed from 2.0. See
elastic/elasticsearch#11195.

See #299

suggester_phrase.go

@@ -28,7 +28,6 @@ type PhraseSuggester struct {
 	tokenLimit              *int
 	preTag, postTag         *string
 	collateQuery            *string
-	collateFilter           *string
 	collatePreference       *string
 	collateParams           map[string]interface{}
 	collatePrune            *bool
@@ -159,11 +158,6 @@ func (q *PhraseSuggester) CollateQuery(collateQuery string) *PhraseSuggester {
 	return q
 }
 
-func (q *PhraseSuggester) CollateFilter(collateFilter string) *PhraseSuggester {
-	q.collateFilter = &collateFilter
-	return q
-}
-
 func (q *PhraseSuggester) CollatePreference(collatePreference string) *PhraseSuggester {
 	q.collatePreference = &collatePreference
 	return q
@@ -283,15 +277,12 @@ func (q *PhraseSuggester) Source(includeName bool) (interface{}, error) {
 		}
 		suggester["highlight"] = hl
 	}
-	if q.collateQuery != nil || q.collateFilter != nil {
+	if q.collateQuery != nil {
 		collate := make(map[string]interface{})
 		suggester["collate"] = collate
 		if q.collateQuery != nil {
 			collate["query"] = *q.collateQuery
 		}
-		if q.collateFilter != nil {
-			collate["filter"] = *q.collateFilter
-		}
 		if q.collatePreference != nil {
 			collate["preference"] = *q.collatePreference
 		}