CHANGELOG 0.13.0 release date

Merge pull request econ-ark#1090 from sbenthall/master

HARK 0.12.0 release commit

Final tweaks

Add more LaTeX definitions to utilities.py

add back index.rst files

drop support for 3.6

Sb 0.10.8 release (econ-ark#861)

* changlog 0.10.8 release date

* update version to 0.10.8

bump up version to 0.10.7 (econ-ark#794)

* Update setup.cfg

* Update __init__.py

bump version number 0.10.6 (econ-ark#630)

* bump version number 0.10.6

* add direct links in README

update changelog with CPM (econ-ark#595)