Support disable console color.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

README.md

@@ -108,6 +108,9 @@ BenchmarkZeus_GithubAll 		| 2000 		| 944234 	| 300688 	| 2648
 
 ```go
 func main() {
+	// Disable Console Color
+	// gin.DisableConsoleColor()
+
 	// Creates a gin router with default middleware:
 	// logger and recovery (crash-free) middleware
 	router := gin.Default()

examples/basic/main.go

@@ -7,6 +7,8 @@ import (
 var DB = make(map[string]string)
 
 func main() {
+	// Disable Console Color
+	// gin.DisableConsoleColor()
 	r := gin.Default()
 
 	// Ping test

logger.go

@@ -22,8 +22,13 @@ var (
 	magenta      = string([]byte{27, 91, 57, 55, 59, 52, 53, 109})
 	cyan         = string([]byte{27, 91, 57, 55, 59, 52, 54, 109})
 	reset        = string([]byte{27, 91, 48, 109})
+	disableColor = false
 )
 
+func DisableConsoleColor() {
+	disableColor = true
+}
+
 func ErrorLogger() HandlerFunc {
 	return ErrorLoggerT(ErrorTypeAny)
 }
@@ -49,7 +54,7 @@ func Logger() HandlerFunc {
 func LoggerWithWriter(out io.Writer, notlogged ...string) HandlerFunc {
 	isTerm := true
 
-	if w, ok := out.(*os.File); !ok || !isatty.IsTerminal(w.Fd()) {
+	if w, ok := out.(*os.File); !ok || !isatty.IsTerminal(w.Fd()) || disableColor {
 		isTerm = false
 	}
 

logger_test.go

@@ -132,3 +132,10 @@ func TestSkippingPaths(t *testing.T) {
 	performRequest(router, "GET", "/skipped")
 	assert.Contains(t, buffer.String(), "")
 }
+
+func TestDisableConsoleColor(t *testing.T) {
+	New()
+	assert.False(t, disableColor)
+	DisableConsoleColor()
+	assert.True(t, disableColor)
+}