GCP-5650
FIX Hibernate objects - ExperimentModel, StockModel, ExperimentStock:
1. use mappedBy attribute in @OneToMany to move ownership to mappedby object
2. use @JoinColumn to declare ownership of relationship
Reference: http://www.mkyong.com/hibernate/inverse-true-example-and-explanation/
Merge branch 'master' of https://github.com/digitalabs/IBPMiddleware