Fixed breakages introduced by astropy-2.0
This PR fixes two problems introduced by the release of astropy v2
- crappy test of
TimeSeriesList.coalescewas exposed, needed fixes - astropy 2 starts using numpy 1.13's new
__array_ufunc__API, so we need to replicate that to get theTimeSeries->StateTimeSeriesconversion to work for numpy ufunc comparisons