remove logcallback (#2513)

Author: tokidoki11

index.d.ts

@@ -63,30 +63,19 @@ declare namespace winston {
     done(info?: any): boolean;
   }
 
-  type LogCallback = (
-    error?: any,
-    level?: string,
-    message?: string,
-    meta?: any
-  ) => void;
-
   interface LogEntry {
     level: string;
     message: string;
     [optionName: string]: any;
   }
 
   interface LogMethod {
-    (level: string, message: string, callback: LogCallback): Logger;
-    (level: string, message: string, meta: any, callback: LogCallback): Logger;
     (level: string, message: string, ...meta: any[]): Logger;
     (entry: LogEntry): Logger;
     (level: string, message: any): Logger;
   }
 
   interface LeveledLogMethod {
-    (message: string, callback: LogCallback): Logger;
-    (message: string, meta: any, callback: LogCallback): Logger;
     (message: string, ...meta: any[]): Logger;
     (message: any): Logger;
     (infoObject: object): Logger;