(#11413) Add spec test for apt::force to verify changes to unless

In the Previous commits, the query being done by the
apt::force install command was not strict enough and
could lead to false positives.

These queries represented by the unless parameter have been
resolved in another commit. This commit accompanies that commit
and adds basic unit tests to correspond to the changes.

spec/defines/force_spec.rb

@@ -0,0 +1,23 @@
+require 'spec_helper'
+describe 'apt::force', :type => :define do
+
+  let :title do
+    'my_package'
+  end
+
+  [false, '1'].each do |version|
+    describe "with version: #{version}" do
+      let :params do
+        {:version => version, :release => 'testing'}
+      end
+      let :unless_query do
+        base_command = "/usr/bin/dpkg -s #{title} | grep -q "
+        base_command + (version ? "'Version: #{params[:version]}'" : "'Status: install'")
+      end
+      let :exec_title do
+        "/usr/bin/aptitude -y -t #{params[:release]} install #{title}"
+      end
+      it { should contain_exec(exec_title).with_unless(unless_query) }
+    end
+  end
+end