Remove obsolete rbx-19mode from Travis
Remove obsolete rbx-19mode from Travis

There are no language modes in Rubinius anymore. Using rbx-2 will run the most recent release of Rubinius 2.x.
astockwell/ruby-net-ldap,bkeepers/ruby-net-ldap,cloudvolumes/ruby-net-ldap,bkeepers/ruby-net-ldap,javanthropus/ruby-net-ldap,astockwell/ruby-net-ldap,javanthropus/ruby-net-ldap,cloudvolumes/ruby-net-ldap