function initFile(file) {
  if (!file.s3) {
    file.s3 = {};
    file.s3.headers = {};
    file.s3.path = file.relative.replace(/\\/g, '/');
  }
  return file;
}
function initFile(file) {
  if (!file.s3) {
    file.s3 = {};
    file.s3.headers = {};
    file.s3.path = file.relative.replace(/\\/g, '/');
  }
  return file;
}
function initFile ( file ) { if ( ! file . s3 ) { file . s3 = { } ; file . s3 . headers = { } ; file . s3 . path = file . relative . replace ( / \\ / g , '/' ) ; } return file ; }
init file s3 hash
@param  {Vinyl} file file object

@return {Vinyl} file
@api private
init file s3 hash @param { Vinyl } file file object