Upgrade shallow-compare to 1.2.2 for React 16 compatibility

[bugzpodder]

The Problem

shallow-compare 1.2.1 has a peer dependency on React 15. It is recently updated in 1.2.2 https://www.npmjs.com/package/shallow-compare which removes this dependency.

Currently RRF has an exact dependency on shallow-compare 1.2.1

Steps to Reproduce

npm install gives a warning: peer invalid: react@15.x, required by shallow-compare@1.2.1

[bugzpodder]

@davidkpiano would love a new release with this change. npm shrinkwrap breaks with any peerDependency warnings. Thanks!

[davidkpiano]

Will do first thing tomorrow.