Remove everything related to SLAmplitudes

nifty5/__init__.py

nifty5/domains/log_rg_space.py

nifty5/operators/exp_transform.py

nifty5/operators/qht_operator.py

nifty5/operators/slope_operator.py

nifty5/operators/symmetrizing_operator.py

nifty5/plot.py

test/test_operators/test_adjoint.py

test/test_operators/test_jacobian.py

test/test_operators/test_representation.py