invariant-0.1.2: README.md

# `invariant` [![Hackage version](https://img.shields.io/hackage/v/invariant.svg?style=flat)](http://hackage.haskell.org/package/invariant) [![Build Status](https://img.shields.io/travis/nfrisby/invariant-functors.svg?style=flat)](https://travis-ci.org/nfrisby/invariant-functors)

Haskell98 invariant functors