New Module: Test cases for ARIMA train and forecast

Pivotal tracker: 54248646 and 55521884

Additional authors:
    Shengwen Yang <syang@gopivotal.com>
    Mark Wellons <mwellons@gopivotal.com>

- Includes input and output tests cases for train and forecast
- Output tests use tsa_beer and tsa_kings_death datasets found in P4
repository