v7.1.0 - Performance upgrade

Performance upgrade

Thanks to @BRKalow and @jacekradko in #129 react-tracking now makes better use of the context API to avoid unnecessary re-renders. If you're on v6 or above, be sure to upgrade! 🔥

Other changes in this release:

In #130 by @tizmagik

• We no longer export ReactTrackingContext, user-land shouldn't need this export given the useTracking hook and track higher-order component (please open an issue if you have a use case!)
• In addition to the default export, you can now also import { track } from 'react-tracking';