v4.0.0-beta.5

Changes

• Remove basename from <StaticRouter> locations
• Add ES build to react-router and react-router-dom (#4432 by @billyjanitsch)
• NavLink exact & strict tests (#4454 by @pshrmn)
• Use boolean strings for cache keys (#4448 by @pshrmn)
• Fix scripts on windows (#4447 by @pshrmn)
• Use peer deps for react-native
• Warn when <Router> is given >1 children (#4450 by @jackfranklin)
• Only nullify empty children array (#4475 by @pshrmn)