tests/engine2_test:

Renamed to `engine_test.py`
engine:

Added functionality to parse sites from a CSV file into the `sites` param.
tests/engine_test:

Added a couple of test cases to exercise reading sites from a sites CSV when
parsing params.
Merge pull request #1113 from larsbutler/sites-csv

Read `sites` from `sites_csv`

[r=matley] [f=1097618]