Add godoc example

example_test.go

@@ -0,0 +1,37 @@
+package fireauth_test
+
+import (
+	"io/ioutil"
+	"log"
+
+	"github.com/LewisWatson/firebase-jwt-auth"
+)
+
+func ExampleVerify() {
+
+	fireauth, err := fireauth.New("example project")
+	if err != nil {
+		log.Fatalf("%v", err)
+	}
+
+	token, err := getToken()
+	if err != nil {
+		log.Fatalf("%v", err)
+	}
+
+	userID, claims, err := fireauth.Verify(token)
+	if err != nil {
+		log.Fatalf("%v", err)
+	}
+
+	log.Printf("userID %v, claims %+v", userID, claims)
+}
+
+func getToken() (string, error) {
+	content, err := ioutil.ReadFile("testdata/token.txt")
+	if err != nil {
+		return "", err
+	}
+
+	return string(content), nil
+}