all: fixed broken tests

1. Use cmp package to replace reflect.DeepEqual
2. db.PutIndex and db.DeleteIndex won't return error when remote_api is
not setup, since they are only called inside db.Put and db.Delete.
db.Search remains unchanged since it is called externally.

Change-Id: Ife84f5a98abe721fbb127e497fdae34125d547a1
Reviewed-on: https://go-review.googlesource.com/78435
Reviewed-by: Ross Light <light@google.com>
21 files changed