add support for go 1.11

docs_test.go

@@ -75,7 +75,8 @@ func testApp() *App {
 func expectFileContent(t *testing.T, file, expected string) {
 	data, err := ioutil.ReadFile(file)
 	// Ignore windows line endings
-	expected = string(bytes.ReplaceAll([]byte(expected), []byte("\r\n"), []byte("\n")))
+	// TODO: Replace with bytes.ReplaceAll when support for Go 1.11 is dropped
+	expected = string(bytes.Replace([]byte(expected), []byte("\r\n"), []byte("\n"), -1))
 	expect(t, err, nil)
 	expect(t, string(data), expected)
 }