Add empty prod profile, move swagger resources

Since we start the application using lein in production it makes sense to add an empty prod profile.

This will allow us to use lein with-profiles prod run :api :process-feed-files :solr-inserts :nrepl :feed-api in order to start the application, this means we will not include any dev resources or src paths.

This issue was highlighted recently because a tokens.edn was added to dev-resources, since we ran the production application using lein run the dev profile was activated and tokens.edn from dev-resources was used, when really we wanted tokens.edn from the regular resources folder.

Adding an explicit profile we can use for production is also useful as no source-paths from the dev profile will be included.

This PR allows us to work around issues we have while still letting us run the application with lein, in the future though, we should probably consider building and running an uberjar.

As part of this PR I've also moved swagger related resources out of doc-resources and into resources/swagger, since this simplifies our resource paths.