Don't pretty-print unparseable test suite types.
Issue #1202. The pretty printer was printing 'type: -' for empty test suite interfaces. The empty test interface type is the result of parsing a branch in a conditional block where no type is explicitly specified (i.e., the type is inherited from a higher level or propagated up from a lower one). Therefore, the pretty-printer should not print any 'type' field at all for test suites with an empty test interface type.