LDAP Public SSH Keys synchronization (#1844)

* Add LDAP Key Synchronization feature

Signed-off-by: Magnus Lindvall <magnus@dnmgns.com>

* Add migration: add login source id column for public_key table

* Only update keys if needed

* Add function to only list pubkey synchronized from ldap

* Only list pub ssh keys synchronized from ldap. Do not sort strings as ExistsInSlice does it.

* Only get keys belonging to current login source id

* Set default login source id to 0

* Some minor cleanup. Add integration tests (updete dep testify)

models/migrations/v66.go

@@ -0,0 +1,22 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import (
+	"fmt"
+
+	"github.com/go-xorm/xorm"
+)
+
+func addLoginSourceIDToPublicKeyTable(x *xorm.Engine) error {
+	type PublicKey struct {
+		LoginSourceID int64 `xorm:"NOT NULL DEFAULT 0"`
+	}
+
+	if err := x.Sync2(new(PublicKey)); err != nil {
+		return fmt.Errorf("Sync2: %v", err)
+	}
+	return nil
+}