def validate!
      unless File.exist?(path)
        raise NoPackageFile.new(path)
      end

      unless File.exist?(metadata.path)
        raise NoPackageMetadataFile.new(metadata.path)
      end

      true
    end
def validate!
      unless File.exist?(path)
        raise NoPackageFile.new(path)
      end

      unless File.exist?(metadata.path)
        raise NoPackageMetadataFile.new(metadata.path)
      end

      true
    end
Validate the presence of the required components for the package.

 @raise [NoPackageFile] if the package is not present
 @raise [NoPackageMetadataFile] if the metadata file is not present

 @return [true]