dev-api: add developer portal, OpenAPI spec, and Flatenbadet case study

- New /developers/ page with API docs, SDKs, pricing, use cases
- OpenAPI 3.0 spec for Orders, Missions, Photos, Analytics
- Case study: Glasskiosken i Flatenbadet — complete ROI analysis
- Updated /order/ with recurring missions and frequency dropdown

services/frilans-payout/node_modules/wrappy/wrappy.js

@@ -0,0 +1,33 @@
+// Returns a wrapper function that returns a wrapped callback
+// The wrapper function should do some stuff, and return a
+// presumably different callback function.
+// This makes sure that own properties are retained, so that
+// decorations and such are not lost along the way.
+module.exports = wrappy
+function wrappy (fn, cb) {
+  if (fn && cb) return wrappy(fn)(cb)
+
+  if (typeof fn !== 'function')
+    throw new TypeError('need wrapper function')
+
+  Object.keys(fn).forEach(function (k) {
+    wrapper[k] = fn[k]
+  })
+
+  return wrapper
+
+  function wrapper() {
+    var args = new Array(arguments.length)
+    for (var i = 0; i < args.length; i++) {
+      args[i] = arguments[i]
+    }
+    var ret = fn.apply(this, args)
+    var cb = args[args.length-1]
+    if (typeof ret === 'function' && ret !== cb) {
+      Object.keys(cb).forEach(function (k) {
+        ret[k] = cb[k]
+      })
+    }
+    return ret
+  }
+}