Add affiliation property to StudyPerson class
Add affiliation property to StudyPerson class

also changes lookups to be based on name/affiliation since that is the unique
constraint

RNAer/qiita,ElDeveloper/qiita,adamrp/qiita,adamrp/qiita,ElDeveloper/qiita,antgonza/qiita,RNAer/qiita,biocore/qiita,antgonza/qiita,RNAer/qiita,ElDeveloper/qiita,josenavas/QiiTa,RNAer/qiita,biocore/qiita,adamrp/qiita,biocore/qiita,josenavas/QiiTa,wasade/qiita,ElDeveloper/qiita,wasade/qiita,squirrelo/qiita,wasade/qiita,squirrelo/qiita,squirrelo/qiita,biocore/qiita,squirrelo/qiita,antgonza/qiita,josenavas/QiiTa,antgonza/qiita,josenavas/QiiTa,adamrp/qiita