Using contain_class instead of include_class

Per rspec-puppet-1.0.1 warning:

DEPRECATION: include_class is deprecated. Use contain_class instead.
Called from .../vendor/gems/rspec-puppet-1.0.1/lib/rspec-puppet/
matchers/include_class.rb:7

Change-Id: I6bc63343597f1b574f9da5beaae187dcc2b3485d
(cherry picked from commit 691e8d755201800707ac4f0c188696b3143f5020)
Merge "Using contain_class instead of include_class" into stable/havana
Merge branch 'stable/havana' of https://github.com/stackforge/puppet-neutron into havana