Upgrade to latest PubSweet versions

• Upgrade dependencies
• Use react-router-dom
• Add rev property to patches (TODO: handle conflicts)
• Update config
• Upgrade webpack
• Update webpack config
• Update hot module reloading
• Update authsome mode (TODO: this is still incomplete, but the existing mode was incomplete and unclear, so I haven't tried to replicate it fully).
• Remove use of refs and other warnings (partial, stopped as it wasn't necessary for this update)
• Use yarn workspaces

TODO: rebase onto origin/master before merging?

Closes #6 (closed)