vendor: add github.com/ncw/dropbox-sdk-go-unofficial and remove github.com/stacktic/dropbox

In due course this will become github.com/dropbox/dropbox-sdk-go-unofficial
when the fate of https://github.com/dropbox/dropbox-sdk-go-unofficial/pull/14
has been decided.

vendor/github.com/ncw/dropbox-sdk-go-unofficial/dropbox/sharing/metadata.go

@@ -0,0 +1,49 @@
+// Copyright (c) Dropbox, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package sharing
+
+import "encoding/json"
+
+type listSharedLinksResult struct {
+	Links   []sharedLinkMetadataUnion `json:"links"`
+	HasMore bool                      `json:"has_more"`
+	Cursor  string                    `json:"cursor,omitempty"`
+}
+
+// UnmarshalJSON deserializes into a ListSharedLinksResult instance
+func (r *ListSharedLinksResult) UnmarshalJSON(b []byte) error {
+	var l listSharedLinksResult
+	if err := json.Unmarshal(b, &l); err != nil {
+		return err
+	}
+	r.Cursor = l.Cursor
+	r.HasMore = l.HasMore
+	r.Links = make([]IsSharedLinkMetadata, len(l.Links))
+	for i, e := range l.Links {
+		switch e.Tag {
+		case "file":
+			r.Links[i] = e.File
+		case "folder":
+			r.Links[i] = e.Folder
+		}
+	}
+	return nil
+}