fix(logging): Prevent IO ex concurrent writes

NuKeeper.Inspection/Logging/FileLogger.cs

@@ -1,11 +1,12 @@
+using NuKeeper.Abstractions.Logging;
 using System;
 using System.IO;
-using NuKeeper.Abstractions.Logging;
 
 namespace NuKeeper.Inspection.Logging
 {
     public class FileLogger : IInternalLogger
     {
+        private readonly object _fileLocker = new object();
         private readonly string _filePath;
         private readonly LogLevel _logLevel;
 
@@ -46,8 +47,9 @@ public void Log(LogLevel level, string message)
 
         private void WriteMessageToFile(string message)
         {
-            using (var w = File.AppendText(_filePath))
+            lock (_fileLocker)
             {
+                using var w = File.AppendText(_filePath);
                 w.WriteLine(message);
             }
         }