This is a maintainance release - bugfixes and upgrades of dependencies.

This release fixes a major issue with leaking file descriptors. Please
upgrade as soon as possible. Ruby 2.1 is required - no other upgrade
issues are known.

bugfixes:
 * #3 handle domains without A-record
 * filedescriptor leak from http_adapters
 * send empty json object on 404 rather than nil
 * remote nicknym is on port 6425
 * use user:password@ prefix in http basic auth

upgrades:
 * require at least ruby 2.1
 * upgrade bundled gems to latest available

tests:
 * more meaningful error messages in case of failures
 * test bundle is up to date
 * regression test for nonexisting domain

integration:
 * Add systemd service unit file
 * Restart nickserver automatically from systemd
 * gitignore: bundle dir

cleanup:
 * old empty adapters and tests