pkg/skel: add rudimentary unit tests

This is an attempt to testing the PluginMain() function of the skel pkg.
We should be able to do better by using a mockable interface for the
plugins, but this is a start.

pkg/skel/skel_suite_test.go

@@ -0,0 +1,13 @@
+package skel
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestSkel(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Skel Suite")
+}