api: Implement bucket notification. (#2271)

* Implement basic S3 notifications through queues

Supports multiple queues and three basic queue types:

1. NilQueue -- messages don't get sent anywhere
2. LogQueue -- messages get logged
3. AmqpQueue -- messages are sent to an AMQP queue

* api: Implement bucket notification.

Supports two different queue types

- AMQP
- ElasticSearch.

* Add support for redis

vendor/gopkg.in/olivere/elastic.v3/search_queries_match_all.go

@@ -0,0 +1,41 @@
+// Copyright 2012-2015 Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+// MatchAllQuery is the most simple query, which matches all documents,
+// giving them all a _score of 1.0.
+//
+// For more details, see
+// https://www.elastic.co/guide/en/elasticsearch/reference/master/query-dsl-match-all-query.html
+type MatchAllQuery struct {
+	boost *float64
+}
+
+// NewMatchAllQuery creates and initializes a new match all query.
+func NewMatchAllQuery() *MatchAllQuery {
+	return &MatchAllQuery{}
+}
+
+// Boost sets the boost for this query. Documents matching this query will
+// (in addition to the normal weightings) have their score multiplied by the
+// boost provided.
+func (q *MatchAllQuery) Boost(boost float64) *MatchAllQuery {
+	q.boost = &boost
+	return q
+}
+
+// Source returns JSON for the function score query.
+func (q MatchAllQuery) Source() (interface{}, error) {
+	// {
+	//   "match_all" : { ... }
+	// }
+	source := make(map[string]interface{})
+	params := make(map[string]interface{})
+	source["match_all"] = params
+	if q.boost != nil {
+		params["boost"] = *q.boost
+	}
+	return source, nil
+}