Add some more tests for the idea project generation

git-svn-id: https://svn.apache.org/repos/asf/buildr/trunk@1526446 13f79535-47bb-0310-9956-ffa450edef68
Use more modern rspec constructs

git-svn-id: https://svn.apache.org/repos/asf/buildr/trunk@1526447 13f79535-47bb-0310-9956-ffa450edef68