Drop running tests on ruby 1.9.3 in travis
Drop running tests on ruby 1.9.3 in travis

Even on container infrastructure, travis uses bundler 1.7.6, which can't
resolve gems properly for ruby 1.9.3. Using bundler 1.14.6 locally, I
can resolve but I was unable to run that version of bundler in travis.

It's probably not worth the effort anyway...

ManageIQ/binary_struct