function buildIncludes(contributors) {
  gutil.log(' ', 'Building include file for each contributor...');
  const keys = Object.keys(contributors);
  keys.forEach(function(key) {
    let contributor = contributors[key];
    contributor.id = key;
    contributor.photo = getPhotoForContributor(key);
    const dest = DEST_INCLUDE.replace('{{key}}', key);
    wfTemplateHelper.renderTemplate(TEMPLATE_INCLUDE, contributor, dest);
  });
  gutil.log('  ', 'Built', gutil.colors.magenta(keys.length + ' files'));
}
Loop through each contributor and render include file for each person.

@param {Array} contributors The list of contributors