Compatibility with auth credentials contains symbols that must be url en...

...coded + test
(please close my recent pull request)

The bug is:

If you don’t do encoding in configuration, then in function relax(opts,callback) row 127:
req.uri = u.resolve(req.uri, encodeURIComponent(opts.db));

req.uri became incorrect.

I have added test to check if resolved by require("url").resolve() url remain correct: "shared_config:url_resolving"