Facilities to build an interceptor chain. This namespace is to
be consumed by other blueprint namespaces.

A data-based registry of specifications for input and commands
in an HTTP API.

A generator of clojure specs for data-based API definitions.

This differs from spec-gen.clj by creating registered specs. So they
are reachable by just using keywords with vanilla the spec api.

* resource specs are in the form of `exoscale.test-api.resource/job`
with for instance one of it's fields:

`exoscale.test-api.resource.job/id` where `exoscale.test-api` is the
blueprint definition root namespace, `job` the resource and `id` one
of its fields.

* commands specs for :update-job-posting are are under:
  - `exoscale.test-api.command.update-job-posting/output`
  - `exoscale.test-api.command.update-job-posting/input`
  - `exoscale.test-api.command.update-job-posting/params`
  - `exoscale.test-api.command.update-job-posting/path`
  - `exoscale.test-api.command.update-job-posting/handler`

* resources
  - `exoscale.test-api.resource/job`
  - `exoscale.test-api.resource/user`