Add missing mysql_root_password to tests/site.pp

Example was missing required parameter mysql_root_password.

Change-Id: I6a6b6e712ccab0057a668f2a3ee007f4483b9d76
Closes-bug: #1263292
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: I63fed009811684de1441a7b9d43325415d1860f9
Merge "Add missing mysql_root_password to tests/site.pp"