Merge branch 'CentralMoments' into 'master'

doc/notebooks/03_tutorial_lbm_formulation.ipynb

...books/10_tutorial_conservative_allen_cahn_two_phase.ipynb

doc/notebooks/demo_create_method_from_scratch.ipynb

doc/sphinx/lbmpy.bib

doc/sphinx/maxwellian_equilibrium.rst

doc/sphinx/tutorials.rst

lbmpy/continuous_distribution_measures.py

lbmpy/creationfunctions.py

lbmpy/cumulants.py

lbmpy/maxwellian_equilibrium.py

lbmpy/methods/__init__.py

lbmpy/methods/abstractlbmethod.py

lbmpy/methods/centeredcumulant/centered_cumulants.py

lbmpy/methods/centeredcumulant/centeredcumulantmethod.py

lbmpy/methods/centeredcumulant/cumulant_transform.py

lbmpy/methods/centeredcumulant/galilean_correction.py

lbmpy/methods/creationfunctions.py

lbmpy/methods/momentbased/centralmomentbasedmethod.py

lbmpy/methods/momentbased/moment_transforms.py

lbmpy/methods/momentbased/momentbasedmethod.py