Unable to run Flutter Launcher Icons without flutter_launcher_icons.yaml file

[MarkOSullivan94]

Hi @RatakondalaArun !
I think I found an issue that can block this release -- I can't run script without having flutter_launcher_icons.yaml.

It seems that the reason for this is in the following code:
https://github.com/fluttercommunity/flutter_launcher_icons/blob/master/lib/main.dart#L184

// Try pubspec.yaml for compatibility
   if (configFile == null) {
     try {
       return loadConfigFile('pubspec.yaml', fileOptionResult);
     } catch (_) {}
   }

configFile can't be null, because it has defaultConfigFile as a default value.

As as result, I always get NoConfigFoundException without flutter_launcher_icons.yaml file.

PR: #398

Originally posted by @p-mazhnik in #397 (comment)

Note: This is only affecting master branch and not a version of Flutter Launcher Icons uploaded to Pub