#1 heroku domain sync

- just added `Contributors`
#1 fixes - main domain being removed

- this fixes the issue of the main domain (and its wildcard) being
removed from Heroku domains
#1 bug fixes
#1 removed the `active` filter
Merge pull request #2 from deanearlbartolabac/herokudomainsync1

#1 wp multisite heroku domain sync
spelling fix
Better link to official source
18 main domain got removed from heroku

- added options to use heroku environment variables
Merge pull request #3 from deanearlbartolabac/18main-domain-got-removed-from-heroku

18 main domain got removed from heroku
updated version number
Create composer.json