Test Gofer.NET with Redis Cluster

[brthor]

This should be able to be done in automated testing in travis, by starting multiple redis hosts locally.

Running the existing test suite against it may suffice but thought should be placed into new potential failure scenarios and test scenarios created to cover them.

The only potential issue I see is with the incoming overhaul to the TaskScheduler that now uses Lua Scripts to promote due scheduled tasks to running tasks. Specifically the SCRIPT LOAD call will likely need to be reworked. Additional research will need to be conducted into how lua scripts interact with Redis Cluster.

/cc @Efp95 from Gitter

[brthor]

After doing some research, it looks like compatibility is possible using hash tags, but precludes many of the benefits of Redis Cluster automatic sharding.