eslint cleanup; trailing comma fix for IE

- Removed unused variables
- Removed double declarations
- Most importantly, removed trailing commas which were breaking IE
- Added eslint.json for future eslint usage
Preserve unused function arguments
Merge pull request #122 from aaronshaf/eslint-cleanup

eslint cleanup; trailing comma fix for IE
[added] animation example

abused the [added] flag just for marketing in the
changelog cause THIS IS EPICLY AWESOME

closes #17
typo
release v0.4.2
manual changelog update

poor CONTRIBUTING.md, all alone with nobody
reading it…
[changed] Split <Routes> component from route spec

Fixes #112.

Test Plan: Loaded each of the examples and clicked around. npm test too.