Merge branch 'new_implementation' into 'master'

.gitlab-ci.yml

docs/RST/examples/stellar.rst

examples/cooling_box/plot_cooling.py

examples/cooling_rate/plot_cooling.py

examples/cooling_rate/run.sh

examples/initial_mass_function/plot_initial_mass_function.py

examples/lifetime/plot_lifetime.py

examples/supernovae_rate/plot_rates.py

examples/supernovae_rate/run.sh

examples/supernovae_yields/plot_yields.py

examples/supernovae_yields/run.sh

pyswiftsim/__init__.py

scripts/pyswift_cooling_rate

scripts/pyswift_initial_mass_function

scripts/pyswift_lifetime

scripts/pyswift_plot_yields

scripts/pyswift_supernovae_rate

setup.py

src/cooling_wrapper.c

src/cooling_wrapper.h