Add parsing of hypervisor deployment tags

Patch include:
* Deployment tag qemu|kvm
  added in  the sanity.test_sanity_infastructure for
  tests: Check internet connectivity from a compute,
  Check DNS resolution on compute node. This give for us
  possibility not discover those tests in case if vcenter
  is set as hypervisor
* Add parsing of hypervisor
  date into fuel_plugin.ostf_adapter.mixin.py
* Add check for  libvrt_data

Related: blueprint vcenter-hv-full-scale-support
Change-Id: Idce25c31c0f001aa1a71fb790b912cddea6fb85b