Updated package metadata, docs/conf.py, and changelog for v1.1.1

CHANGELOG: initial commit of changelog

setup: incremented version to for snapshot going to PyPI

verify: moved threat score location in Contingency2x2 summary output

Threat score is an accuracy metric, equitable threat score is a skill score
using threat score as the accuracy metric and TS for a random forecast as the
reference. Threat score was therefore moved to 'stats' while ETS stayed in
'skill' on printing the verbose summary output.