added forced contact override
Merge branch 'master' of https://github.com/Minds-On-Design-Lab/givingimpact-php

# By keston (7) and Mike Joseph (1)
# Via keston
* 'master' of https://github.com/Minds-On-Design-Lab/givingimpact-php:
  updated readme
  updated readme
  updated readme
  updated readme
  contact must be non-empty
  moved readme changes to the right branch
  wrong branch
  updated docs with Custom checkout for donations info

Conflicts:
	MODL/GivingImpact/Model/Donation.php