feat(clap): setup infrastructure

This allows us to setup clap and see if it compiles, which is the prime
goal of the current workflow step.

Related to #81

etc/api/type-cli.yaml

@@ -26,8 +26,7 @@ cargo:
   keywords: [cli]
   is_executable: YES
   dependencies:
-    - docopt = "*"
-    - docopt_macros = "*"
+    - clap = "*"
     - rustc-serialize = "*"
     - yup-hyper-mock = "*"
     - serde = ">= 0.3.0"