PROTON-352: Fixed the runtime environment for Ruby spec tests in Cmake.

The tests were not being run in the bindings/ruby directory, which
caused Rspec to fail to find the actual tests. The test now runs in the
ruby directory itself.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1503700 13f79535-47bb-0310-9956-ffa450edef68
QPID-355: Fixed the broken Rspec tests.

Removed a few tracker spec tests since the expectation has changed. Also
removed the negative receive limit since that's no longer an exceptional
case.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1503701 13f79535-47bb-0310-9956-ffa450edef68