Adds React Context Provider

[taylorjdawson]

Description

Adds a Web3OnboardProvider for global state management with React contexts.

Example:

function App() {
  return (
    <Web3OnboardProvider web3Onboard={web3Onboard}>
      <YourApp />
    </Web3OnboardProvider>
  )
}

Checklist

• The version field in package.json is incremented following semantic versioning
• I tested locally to make sure this feature/fix works
• I have run yarn type-check & yarn build to confirm there are not any associated errors
• This PR passes the Circle CI checks

[Adamj1232]

Looks good! React package version needs a bumperino

[Adamj1232]

LesGO!