Replace test.attr() with decorators.attr()

Function 'tempest.test.attr()' has been moved to'tempest.lib.decorators.attr()'
in Pike and will be removed in a future version [1]. This patch is to replace
'tempest.test.attr()' with 'tempest.lib.decorators.attr()'.

[1] Iaafbb112b6eee458089cc49918359a8a8d0485e2

Depends-On: I50b823b049d0e391ac517f7ec72380a12fa81176
Change-Id: I1e511166a114a79504404c88579f6cb0c4caaebe
17 files changed
tree: 83273f52e6bac1f84cf9e1a49bcd1538af1f3b3b
  1. neutron/