Add support for Function and Trigger domain objects (#1060)

Vast commit, includes:

 * Introduces the Trigger domain entity.
 * Introduces the Fns domain entity.
 * V2 of the API for interacting with the new entities in swaggerv2.yml
 * Adds v2 end points for Apps to support PUT updates.
 * Rewrites the datastore level tests into a new pattern.
 * V2 routes use entity ID over name as the path parameter.

api/models/trigger_test.go

@@ -0,0 +1,51 @@
+package models
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+var openEmptyJson = `{"id":"","name":"","app_id":"","fn_id":"","created_at":"0001-01-01T00:00:00.000Z","updated_at":"0001-01-01T00:00:00.000Z","type":"","source":""`
+
+var triggerJsonCases = []struct {
+	val       *Trigger
+	valString string
+}{
+	{val: &Trigger{}, valString: openEmptyJson + "}"},
+}
+
+func TestTriggerJsonMarshalling(t *testing.T) {
+	for _, tc := range triggerJsonCases {
+		v, err := json.Marshal(tc.val)
+		if err != nil {
+			t.Fatalf("Failed to marshal json into %s: %v", tc.valString, err)
+		}
+		if string(v) != tc.valString {
+			t.Errorf("Invalid trigger value, expected %s, got %s", tc.valString, string(v))
+		}
+	}
+}
+
+var httpTrigger = &Trigger{Name: "name", AppID: "foo", FnID: "bar", Type: "http", Source: "baz"}
+var invalidTrigger = &Trigger{Name: "name", AppID: "foo", FnID: "bar", Type: "error", Source: "baz"}
+
+var triggerValidateCases = []struct {
+	val   *Trigger
+	valid bool
+}{
+	{val: &Trigger{}, valid: false},
+	{val: invalidTrigger, valid: false},
+	{val: httpTrigger, valid: true},
+}
+
+func TestTriggerValidate(t *testing.T) {
+	for _, tc := range triggerValidateCases {
+		v := tc.val.Validate()
+		if v != nil && tc.valid {
+			t.Errorf("Expected Trigger to be valid, but err (%s) returned. Trigger: %#v", v, tc.val)
+		}
+		if v == nil && !tc.valid {
+			t.Errorf("Expected Trigger to be invalid, but no err returned. Trigger: %#v", tc.val)
+		}
+	}
+}