Feature/transitions builder

[johnameyer]

Closes #113

Work to be done still:

• [ ] Change state variables to be a list of strings (not joined string)
• [ ] Figure out how handleRoundRobin will track state
  • Maybe we just tell it which controller to use a la can-i-have-that
• [ ] Figure out names (sequence)
• [ ] Hide direct access to state, waiting, players handlers
• [ ] Figure out top level struct (i.e. start/end game and appropriate logic - e.g. complete())
• [ ] Clarify beforeEach / sequence type idiosyncrasies
• [ ] Consider if necessary to remove empty nodes or if these can be avoided outright
  • Main concern is naturally around loops where we don't currently want an end node to be conditional
  • Possibly we can use some placeholder flag if need be
• [ ] Standardize testing mocks/constructs between these tests and the driver tests
• [ ] Trick construct (or others?)
• [ ] Implement for every game handler and verify behavior
• [ ] (stretch) Generate mermaid diagram