def list(latest = false)
      result = []
      @os.map do |os, versions|
        unless latest
          versions.each { |version| result << {os: os, version: version}}
        else
          result << {os: os, version: versions.last} if versions.length > 0
        end
      end
      result
    end
def list(latest = false)
      result = []
      @os.map do |os, versions|
        unless latest
          versions.each { |version| result << {os: os, version: version}}
        else
          result << {os: os, version: versions.last} if versions.length > 0
        end
      end
      result
    end
Returns list of available os versions
 @param [TrueClass, FalseClass] latest specify if would like to receive only latest
 @return [Array<Hash{Symbol => String, Symbol}>] list of os versions in view of hash