aact-345: Remove migration script that creates foreign keys.  We always drop indexes/constraints before each load & then DbManager recreates them. By having them defined in a migration script, we duplicate the process and need to synchronize the index names here with the names assigned by DbManager. Also, there’s no point in adding indexes to an empty database that will all be dropped when the db is first loaded.  
aact-345: Remove migration script that creates foreign keys.  We always drop indexes/constraints before each load & then DbManager recreates them. By having them defined in a migration script, we duplicate the process and need to synchronize the index names here with the names assigned by DbManager. Also, there’s no point in adding indexes to an empty database that will all be dropped when the db is first loaded.  
tibbs001/aact-1,tibbs001/aact-1,ctti-clinicaltrials/aact,ctti-clinicaltrials/aact,tibbs001/aact-1,ctti-clinicaltrials/aact