Added 'defaults.py' which contains default values for some of the input arguments.

toarstats/defaults.py

+"""Collection of default values for the package.
+
+This module contains the following constants:
+DEFAULT_SEASONS - default list of seasons
+DEFAULT_CROPS - default list of crops
+DEFAULT_DATA_CAPTURE - default data capture value
+"""
+
+DEFAULT_SEASONS = ["DJF", "MAM", "JJA", "SON"]
+DEFAULT_CROPS = ["wheat", "rice"]
+DEFAULT_DATA_CAPTURE = 0.75