[repository] perform Kerberos login

[costin]

What kind an issue is this?

• Feature Request. Start by telling us what problem you’re trying to solve.
  Often a solution already exists! Don’t send pull requests to implement new features without
  first getting our support. Sometimes we leave features out on purpose to keep the project small.

Issue description

The repository setup could be simplified by performing the SecurityUtil.login based on a user defined keytab and principal. While these properties can be set, calling the login method directly in the plugin should simplify things.