It is possible to connect two single solenoids to a single Spike, and control them independently. See here for the wiring diagram:
http://www.ifirobotics.com/docs/spik...uide-sep05.pdf on page 2.
Please note that this has been a legal setup in the past, but rules from prior years do not apply to this year. I can't comment on the legality at this time, and your best bet will be to ask the official Q&A.
FYI, using the referenced setup above, you'll quickly discover that you can actually run a Spike relay in both forward and reverse at the same time. This brings both output pins high to 12V, which would activate both solenoids simultaneously.