Add build even if release not specified explicitly
Add build even if release not specified explicitly

Function addBuilds() gets release from parameter kwargs. If there
is not the 'release' key, it throws an exception. Errata includes
release parameter (self._release), thus it is not necessary to specify
it explicitly.

Use self._release as release if kwargs["release"] not specified.

mmuzila/errata-tool,mmuzila/errata-tool