Fix ``merge`` so that trailing ``{}`` or ``[]`` don't overwrite previous source values.
Remove "*" character from docstrings. Having them results in those parameters missing in docs build.
Add py_ as alias of _.
Release v2.3.1.
Merge branch 'develop' of github.com:dgilland/pydash into develop

Conflicts:
	CHANGES.rst
Add missing pipe and pipe_right to __all__.