added units to test_simulation.py

[mishinma]

I just added some units to tests in test_simulation.py. This seems to resolve the issue #478

[yeganer]

I'm fine with that change and i think we should use assert_quantity_allclose whenever possible.

@wkerzendorf @unoebauer Any comments? If you are fine i think we should merge.

[mishinma]

Do we need to pass atol=0.0 in every assert statement? Its default value is 0 already.
And when providing atol value to assert_quantity_allclose one must specify units because of the implementation in Astropy:

if atol is None:
        # by default, we assume an absolute tolerance of 0
        atol = u.Quantity(0)
    else:
        atol = u.Quantity(atol, subok=True, copy=False)
        try:
            atol = atol.to(actual.unit)
        except u.UnitsError:
            raise u.UnitsError("Units for 'atol' ({0}) and 'actual' ({1}) "
                               "are not convertible"
                               .format(atol.unit, actual.unit))

[unoebauer]

Looks very good - thanks for the effort @mishinma.

I am wondering, though, if (maybe for future reference) it would make more sense to generate a proper reference data set, containing quantities instead of bare numpy arrays. Thoughts on this, @wkerzendorf, @yeganer?

[wkerzendorf]

@unoebauer - yes it would make sense to do this, however it's not clear how to store those. But for now we are merging this.