Allow status to be specified with symbols

[tobiashm]

Let the status helper accept symbols representing HTTP status codes, by looking up the numeric status code in Rack::Utils

This allows you to e.g. specify status :accepted instead of status 202, so readers of your code doesn't have to remember less used status codes.

[kgrz]

👍

Just one nitpick: any reason not to use the status_code method that's provided in the Rack::Utils module? It seems to default to 500 error if the symbol provided is not present in the hash.

[tobiashm]

@kgrz No, that looks even better. Will update PR.

[zzak]

@tobiashm LGTM, thank you!

[iainbeeston]

Is there any way to extend this to the return values of route blocks as well? It'd be great to be able to do something like return [:ok, 'Looks good to me']. I've had a brief attempt at this (by pulling the changes from this PR down into Response#status=) but that didn't work. I'm happy to write a patch if anyone can suggest the best place to make the change.