Prepare for new release.

Update version.

Prepare for first stable release.

Merge remote-tracking branch 'origin/master'

# Conflicts:
#	docs/reference/R/coalescent.ipynb
#	docs/reference/R/demography.ipynb
#	docs/reference/R/exponentiation_backend.rst
#	docs/reference/R/mutation_configs.ipynb
#	docs/reference/R/quickstart.ipynb
#	docs/reference/R/rewards.ipynb
#	phasegen/distributions.py
#	phasegen/norms.py

Prepare for new release.

Change formatting.

Prepare for new beta release.

Prepare for new release.

Prepare for new beta release.

Prepare for new release.