all, travis: build against 1.6, require no messages from gofmt, govet

Also disables tip because gimme is broken. See travis-ci/gimme#38.

Change-Id: I1a757c6e15827a6861d949c3896e35bf7d62d878

.travis.yml

@@ -2,4 +2,14 @@ language: go
 
 go:
   - 1.5.3
-  - tip
+  - 1.6
+# - tip # NOTE: disabled - see https://github.com/travis-ci/gimme/issues/38
+
+install:
+  - go get golang.org/x/tools/cmd/vet
+  - go get github.com/golang/lint/golint
+
+script:
+  - go test -v ./...
+  - go vet ./...
+  - GOFMT=$(gofmt -d -s .) && echo $GOFMT && test -z "$GOFMT"

docs/appengine/mail/mailgun/mailgun.go

@@ -28,7 +28,7 @@ func SendSimpleMessageHandler(w http.ResponseWriter, r *http.Request) {
 		/* To */ "[email protected]", "YOU@YOUR_DOMAIN_NAME",
 	))
 	if err != nil {
-		msg := fmt.Sprintf("Could not send message: %v, ID %d, %+v", err, id, msg)
+		msg := fmt.Sprintf("Could not send message: %v, ID %v, %+v", err, id, msg)
 		http.Error(w, msg, http.StatusInternalServerError)
 		return
 	}
@@ -61,7 +61,7 @@ func SendComplexMessageHandler(w http.ResponseWriter, r *http.Request) {
 
 	msg, id, err := mg.Send(message)
 	if err != nil {
-		msg := fmt.Sprintf("Could not send message: %v, ID %d, %+v", err, id, msg)
+		msg := fmt.Sprintf("Could not send message: %v, ID %v, %+v", err, id, msg)
 		http.Error(w, msg, http.StatusInternalServerError)
 		return
 	}

docs/managed_vms/analytics/analytics.go

@@ -40,10 +40,10 @@ func handle(w http.ResponseWriter, r *http.Request) {
 
 func trackEvent(r *http.Request, category, action, label string, value *uint) error {
 	if gaPropertyID == "" {
-		return errors.New("analytics: GA_TRACKING_ID environment variable.")
+		return errors.New("analytics: GA_TRACKING_ID environment variable is missing")
 	}
 	if category == "" || action == "" {
-		return errors.New("analytics: category and action are required.")
+		return errors.New("analytics: category and action are required")
 	}
 
 	v := url.Values{

docs/managed_vms/mailgun/mailgun.go

@@ -56,7 +56,7 @@ func sendSimpleMessageHandler(w http.ResponseWriter, r *http.Request) {
 		/* To */ "[email protected]", "YOU@"+mailgunDomain,
 	))
 	if err != nil {
-		msg := fmt.Sprintf("Could not send message: %v, ID %d, %+v", err, id, msg)
+		msg := fmt.Sprintf("Could not send message: %v, ID %v, %+v", err, id, msg)
 		http.Error(w, msg, http.StatusInternalServerError)
 		return
 	}
@@ -79,7 +79,7 @@ func sendComplexMessageHandler(w http.ResponseWriter, r *http.Request) {
 
 	msg, id, err := mailgunClient.Send(message)
 	if err != nil {
-		msg := fmt.Sprintf("Could not send message: %v, ID %d, %+v", err, id, msg)
+		msg := fmt.Sprintf("Could not send message: %v, ID %v, %+v", err, id, msg)
 		http.Error(w, msg, http.StatusInternalServerError)
 		return
 	}

getting-started/bookshelf/db_memory.go

@@ -71,7 +71,7 @@ func (db *memoryDB) DeleteBook(id int64) error {
 	defer db.mu.Unlock()
 
 	if _, ok := db.books[id]; !ok {
-		return fmt.Errorf("memorydb: could not delete book with ID %d, does not exist.", id)
+		return fmt.Errorf("memorydb: could not delete book with ID %d, does not exist", id)
 	}
 	delete(db.books, id)
 	return nil
@@ -103,7 +103,7 @@ func (db *memoryDB) ListBooks() ([]*Book, error) {
 	db.mu.Lock()
 	defer db.mu.Unlock()
 
-	books := make([]*Book, 0)
+	var books []*Book
 	for _, b := range db.books {
 		books = append(books, b)
 	}

getting-started/bookshelf/db_mysql.go

@@ -163,7 +163,7 @@ func (db *mysqlDB) ListBooks() ([]*Book, error) {
 	}
 	defer rows.Close()
 
-	books := make([]*Book, 0)
+	var books []*Book
 	for rows.Next() {
 		book, err := scanBook(rows)
 		if err != nil {
@@ -193,7 +193,7 @@ func (db *mysqlDB) ListBooksCreatedBy(userID string) ([]*Book, error) {
 	}
 	defer rows.Close()
 
-	books := make([]*Book, 0)
+	var books []*Book
 	for rows.Next() {
 		book, err := scanBook(rows)
 		if err != nil {