Remove use of deprecated include_class matcher

include_class is deprecated since rspec-puppet 1.0.0.
contain_class should be used instead.

Closes-bug: #1263617
Change-Id: If2e5a2c467a5d1c4eb130dc6b2643d05c748abe0
(cherry picked from commit f745cf634fa2cf9889a2ef03ee9de3a3d0d1045b)
Merge "Remove use of deprecated include_class matcher" into stable/havana