docs: def package(self):
          """Packages lambda data for deployment into a zip"""
          logger.info('Packaging lambda {}'.format(self.lambda_name))
          zfh = io.BytesIO()
  
          if os.path.exists(os.path.join(self.lambda_dir, '.env')):
              logger.warn(
                  'A .env file exists in your Lambda directory - be '
                  'careful that it does not contain any secrets you '
                  'don\'t want uploaded to AWS!'
              )
  
          with zipfile.ZipFile(zfh, 'w') as zf:
              self.add_directory_to_zip(self.lambda_dir, zf)
  
              # Construct a .env file in the archive with our
              # needed envrionment variables.
              envinfo = zipfile.ZipInfo('.env')
              envinfo.external_attr = 0644 << 16L
              zf.writestr(
                  envinfo,
                  '\n'.join(
                      '{} = {}'.format(key, yaep.env(key))
                      for key in self.env_vars
                  )
              )
  
              if 'requirements.txt' in os.listdir(self.lambda_dir):
                  with TemporaryDirectory() as temp_dir:
                      pip_args = [
                          'install',
                          '-r',
                          os.path.join(self.lambda_dir, 'requirements.txt'),
                          '-t',
                          temp_dir
                      ]
  
                      # Do pip install to temporary dir
                      if pip.main(pip_args) == 0:
                          self.add_directory_to_zip(temp_dir, zf)
                      else:
                          if sys.platform == 'darwin':
                              logger.error(
                                  'A DistutilsOptionError about the prefix '
                                  'can occur when you are on OS X and '
                                  'installed Python via Homebrew.\nIf this '
                                  'is you, please look at https://github.com'
                                  '/Homebrew/brew/blob/master/share/doc/'
                                  'homebrew/Homebrew-and-Python.md'
                                  '#note-on-pip-install---user\n'
                                  'If this is not you, please contact us '
                                  ' for support.'
                              )
                          raise DependencyInstallationError(
                              'Failed to install dependencies of {}'.format(
                                  self.lambda_name
                              )
                          )
  
          zfh.seek(0)
  
          return zfh