Added locales output to enable pipping to other tasks
Added locales output to enable pipping to other tasks

Example:

```
task: {
  options: {
    languages: "<%= i18n_gspreadsheet.data.locales %>"
  }
}
```

marcbuils/gulp-i18n-gspreadsheet,marcbuils/grunt-i18n-gspreadsheet,andyhawkes/grunt-i18n-gspreadsheet,theoephraim/grunt-i18n-gspreadsheet