SciPy error when running "Usecase 3" notebook

[karalekas]

When running cell 11, I get the following:

/Users/peter/.pyenv/versions/3.8.5/envs/pulser/lib/python3.8/site-packages/scipy/integrate/_ode.py:1011: UserWarning: zvode: Excess work done on this call. (Perhaps wrong MF.)
  warnings.warn('{:s}: {:s}'.format(self.__class__.__name__,
---------------------------------------------------------------------------
Exception                                 Traceback (most recent call last)
<ipython-input-11-85845f327bc1> in <module>
     10 
     11 total_duration = max([seq._last(ch).tf for ch in seq._schedule])
---> 12 output = qutip.sesolve(H, psi0, range(total_duration), [observable])

~/.pyenv/versions/3.8.5/envs/pulser/lib/python3.8/site-packages/qutip/sesolve.py in sesolve(H, psi0, tlist, e_ops, args, options, progress_bar, _safe_mode)
    167         func(0., v, *ode_args) + v
    168 
--> 169     res = _generic_ode_solve(func, ode_args, psi0, tlist, e_ops, options,
    170                              progress_bar, dims=psi0.dims)
    171     if e_ops_dict:

~/.pyenv/versions/3.8.5/envs/pulser/lib/python3.8/site-packages/qutip/sesolve.py in _generic_ode_solve(func, ode_args, psi0, tlist, e_ops, opt, progress_bar, dims)
    346         progress_bar.update(t_idx)
    347         if not r.successful():
--> 348             raise Exception("ODE integration error: Try to increase "
    349                             "the allowed number of substeps by increasing "
    350                             "the nsteps parameter in the Options class.")

Exception: ODE integration error: Try to increase the allowed number of substeps by increasing the nsteps parameter in the Options class.

[sebgrijalva]

It should be running now, I updated the file on PR #20