Feature: redirections

[eric-burel]

Hi,
I open this issue to discuss about the best API for route redirection. I propose an API like addRoute({ path:'/old-path', redirectPath:'/new-path' }), based on discussions in #2091.

We can render a <Redirect/> when we detect the redirectPath prop (see App.jsx in the apollo2 branch, which uses React Router 4), the implementation is trivial.

However, with this we only handle redirection within React router. So, you can setup a "real" redirection. E.g if you had a blog in your Vulcan app, but moved it to another technology/server, you won't be able to redirect to it with this syntax. For example, I could not redirect the /graphiql endpoint, which will disappear with Apollo2, to the new endpoint, because the related routes lives outside the router (GraphQL Playground/GraphiQL are literally new apps within the Vulcan app).

So my questions are:

• are you ok with a redirectPath option in the addRoute function?
• do you think supporting "real" redirection is worth it? I think they would need another param like external:true to differentiate them from React Router routes.