LEAP12/SLE12: hawk

Features:

• Allow also users in haclient to view history explorer (#214)

• Disable TLS 1.0 and TLS 1.1 via puma (#217). This differ for SLE15 versions.
  This allows to disable via puma config disabling TLS 1.0 and TLS.1.1. (see https://gist.github.com/MalloZup/f7cd3020e1165c800a4323860e8acb86) for documentation howto.

Bugfixes:

• handle properly in the webui when a Cluster resource has the same name of a node of cluster (#210)