Merge branch 'D3Q7' into 'master'

doc/notebooks/03_tutorial_lbm_formulation.ipynb

doc/notebooks/04_tutorial_cumulant_LBM.ipynb

doc/notebooks/07_tutorial_thermal_lbm.ipynb

doc/notebooks/09_tutorial_shanchen_twocomponent.ipynb

lbmpy/boundaries/boundaryconditions.py

lbmpy/continuous_distribution_measures.py

lbmpy/creationfunctions.py

lbmpy/enums.py

lbmpy/forcemodels.py

lbmpy/maxwellian_equilibrium.py

lbmpy/methods/conservedquantitycomputation.py

lbmpy/methods/creationfunctions.py

lbmpy/methods/default_moment_sets.py

lbmpy/methods/momentbased/momentbasedmethod.py

lbmpy/moments.py

lbmpy/stencils.py

lbmpy_tests/test_weights.py