Add dataset sanity checks before model creation

The sanity check happens right before self.data is passed to bmb.Model. The following checks need to be performed:

[x] We assume that the first column is always rt (self.response[0] == "rt")
[x] All response columns should exist in data, including deadline
[x] All decisions (-1 and 1) should exist in data
[x] When hierarchical is set to True, participant_id should exist in data
[x] When deadline and missing_data are both set to False, there should not be -999.0
[x] When at least one of deadline and missing_data is True, there should be -999.0 in data

lnccbrown / HSSM