Change loadClientOrDie to return an error

Also remove a bunch of dead code. This is a step along the path to
getting rid of all the glog in util.go.

test/e2e/pods.go

@@ -36,7 +36,9 @@ var _ = Describe("Pods", func() {
 	)
 
 	BeforeEach(func() {
-		c = loadClientOrDie()
+		var err error
+		c, err = loadClient()
+		Expect(err).NotTo(HaveOccurred())
 	})
 
 	It("should be submitted and removed", func() {