load method
Will load the environment variables asynchrosnously
Implementation
Future<bool> load() async {
File envFile = File('$path$separator${_formatName()}');
if (!await envFile.exists()) {
throw FileSystemException('File ${envFile.path} nout found !');
}
List<String> lines = await envFile.readAsLines();
_fillEnvMap(lines);
return true;
}