Generate unique uuid for migrated snippets

with simple ruby code:

regex = /\w+-\w+-\w+-\w+/i

files = Dir['*.tmSnippet']

files.each do |file|
  new_uuid = `uuidgen`.sub("\n", '')

  new_content = File.read(file).
    sub(regex, new_uuid)

  File.open(file, 'w') do |out|
    out << new_content
  end
end