feat(CLI):required arg parsing + first doit() call

We are parsing required scalar values and handle parse-errors correctly,
to the point were we make a simple, non-upload doit() call.

It shows that we seem to build invalid calls, for now,but that's nothing
we can't fix once the time is ripe.

Next goals will be related to finalizing the argument parsing code.

Fixes #60

etc/api/type-api.yaml

@@ -1,10 +1,5 @@
 api:
   base_path: "etc/api"
-  terms:
-    # how to actually do something with the API
-    action: doit
-    # when a resource is supposed to be uploaded
-    upload_action: upload
   properties:
     # additional fields specified by the user
     params: '_additional_params'