This commit includes functionality for many of the models that the
program will use. The transaction model, rate, and room model have been
implemented, but still need further review to determine if they are
finished. The same applies to guest and reservation. Currently all
models include a simple list class, the decision to use a database or
a serialized object (JSON, array, list, etc). These lists are currently
a placeholder and are not guaranteed to land in main.
