postgresql 9.4.4 serialization failure due to FK

postgresql 9.4.4 serialization failure due to FK

Files:
setup.sql - http://pastebin.com/24dgELYa
run.sh - http://pastebin.com/3BsQtc3S

Test steps:

createdb test
psql test -f setup.sql
./run.sh

Output - eventually one or more:

ERROR:  could not serialize access due to read/write dependencies among transactions
DETAIL:  Reason code: Canceled on commit attempt with conflict in from prepared pivot.
HINT:  The transaction might succeed if retried.
ERROR:  could not serialize access due to read/write dependencies among transactions
DETAIL:  Reason code: Canceled on commit attempt with conflict in from prepared pivot.
HINT:  The transaction might succeed if retried.