make context.Keys available as LogFormatterParams (#1779)

* make context available as LogFormatterParams

* pass context Keys to LogFormatterParams

* update logger test to check for Key param

logger.go

@@ -66,6 +66,8 @@ type LogFormatterParams struct {
 	IsTerm bool
 	// BodySize is the size of the Response Body
 	BodySize int
+	// Keys are the keys set on the request's context.
+	Keys map[string]interface{}
 }
 
 // StatusCodeColor is the ANSI color for appropriately logging http status code to a terminal.
@@ -227,6 +229,7 @@ func LoggerWithConfig(conf LoggerConfig) HandlerFunc {
 			param := LogFormatterParams{
 				Request: c.Request,
 				IsTerm:  isTerm,
+				Keys:    c.Keys,
 			}
 
 			// Stop timer