Exclude auth for root path only

[tadejm]

Hey @eparreno 👋

Merging this PR will allow a dev to exclude the root path ('/') without excluding all paths starting with a / from the JWT token auth check. This comes handy when we want to have a pretty landing/docs page mounted on / and an JWT auth API that serves from other paths, i.e. /users.

[berkes]

I like and need this exact case.

Anything I can do to push this forward and help getting this merged?

For example, I could make it more generic using a regex instead of start_with()? e.g. |ex| env['PATH_INFO'].match?(ex) that would probably degrade performance and not be backwards compatible, but does give implementers more freedom.

Alternatively, a switch based on wether it is a string, or a regex:

        @exclude.any? { |ex|
          path = env['PATH_INFO']
          ex.is_a?(String) && path.start_with?(ex) || ex.is_a?(Regexp) && path.match?(ex)
       }

But then a tad more readable :)

[berkes]

Anything we can do to help get this merged?