Update type expectation from latest GCCXML
Add a Gemfile
Add <NamespaceAlias> nodes to simply be a <Namespace> node

Fixes jasonroelofs/rbplusplus#20
Fix deprecation warning with should_not raise_error

Honestly such a check doesn't make sense, so removing the check
altogether. Also remove a pending test that's been pending for a very
long time!
Update test to be more reliable across architectures

Travis started failing because the list of constructors started coming
back different than the test was expecting.