Bug when minimizer_kwargs is empty but the minimizer is not optimize.minimize

[artix41]

When I try to use QAOA with scipy.optimize.fmin_l_bfgs_b as my minimizer and no minimize_kwargs (I want to use the default argument), I get the error:
fmin_l_bfgs_b() got an unexpected keyword argument 'method'

it's due to this line in grove/qaoa.py:

self.minimizer_kwargs = minimizer_kwargs or {
            'method': 'Nelder-Mead',
            'options': {
                'disp': True,
                'ftol': 1.0e-2,
                'xtol': 1.0e-2
            }
}

It should be replace by a more complex condition that verify if the minimizer is indeed optimize.minimize