Load schema before assertion
Load schema before assertion

Without this, test fails because the load schema when pluck is executed.

Steps to reproduce:

```
bin/test -a postgresql -w --seed 61689 test/cases/*test.rb -n "/^(?:InheritanceComputeTypeTest#(?:test_inheritance_new_with_subclass_as_default)|CalculationsTest#(?:test_pluck_loaded_relation))$/"

# Running:

.F

Failure:
CalculationsTest#test_pluck_loaded_relation [/home/yaginuma/program/rails/master_y_yagi/rails/activerecord/test/cases/calculations_test.rb:722]:
1 instead of 0 queries were executed.
Queries:
SELECT c.relname FROM pg_class c LEFT JOIN pg_namespace n ON n.oid = c.relnamespace WHERE n.nspname = ANY (current_schemas(false)) AND c.relname = 'companies' AND c.relkind IN ('r','v','m').
Expected: 0
  Actual: 1

bin/test test/cases/calculations_test.rb:7
```

baerjam/rails,ledestin/rails,eileencodes/rails,mohitnatoo/rails,yasslab/railsguides.jp,untidy-hair/rails,printercu/rails,arunagw/rails,fabianoleittes/rails,vipulnsward/rails,assain/rails,rafaelfranca/omg-rails,baerjam/rails,notapatch/rails,shioyama/rails,illacceptanything/illacceptanything,gfvcastro/rails,gauravtiwari/rails,palkan/rails,Edouard-chin/rails,arunagw/rails,tjschuck/rails,baerjam/rails,repinel/rails,kaspth/rails,yasslab/railsguides.jp,Stellenticket/rails,starknx/rails,Envek/rails,georgeclaghorn/rails,deraru/rails,pvalena/rails,gcourtemanche/rails,yalab/rails,Erol/rails,gfvcastro/rails,Erol/rails,kmcphillips/rails,eileencodes/rails,shioyama/rails,alecspopa/rails,Vasfed/rails,gauravtiwari/rails,yawboakye/rails,yahonda/rails,Envek/rails,notapatch/rails,rails/rails,Sen-Zhang/rails,MSP-Greg/rails,esparta/rails,bogdanvlviv/rails,rails/rails,BlakeWilliams/rails,notapatch/rails,Sen-Zhang/rails,joonyou/rails,illacceptanything/illacceptanything,betesh/rails,prathamesh-sonpatki/rails,yawboakye/rails,travisofthenorth/rails,kmcphillips/rails,tjschuck/rails,esparta/rails,prathamesh-sonpatki/rails,rails/rails,betesh/rails,tgxworld/rails,fabianoleittes/rails,pvalena/rails,illacceptanything/illacceptanything,iainbeeston/rails,illacceptanything/illacceptanything,yahonda/rails,shioyama/rails,odedniv/rails,mohitnatoo/rails,lcreid/rails,EmmaB/rails-1,esparta/rails,Edouard-chin/rails,palkan/rails,kmayer/rails,fabianoleittes/rails,aditya-kapoor/rails,kirs/rails-1,BlakeWilliams/rails,yasslab/railsguides.jp,mathieujobin/reduced-rails-for-travis,aditya-kapoor/rails,kmayer/rails,lcreid/rails,georgeclaghorn/rails,illacceptanything/illacceptanything,felipecvo/rails,utilum/rails,betesh/rails,untidy-hair/rails,printercu/rails,tgxworld/rails,yhirano55/rails,pvalena/rails,illacceptanything/illacceptanything,printercu/rails,gauravtiwari/rails,yawboakye/rails,assain/rails,Erol/rails,rails/rails,palkan/rails,travisofthenorth/rails,lcreid/rails,kddeisz/rails,brchristian/rails,kmcphillips/rails,kddeisz/rails,Vasfed/rails,schuetzm/rails,untidy-hair/rails,odedniv/rails,jeremy/rails,Edouard-chin/rails,yasslab/railsguides.jp,joonyou/rails,baerjam/rails,prathamesh-sonpatki/rails,illacceptanything/illacceptanything,Envek/rails,kmayer/rails,kamipo/rails,repinel/rails,starknx/rails,untidy-hair/rails,mechanicles/rails,gfvcastro/rails,felipecvo/rails,repinel/rails,assain/rails,tgxworld/rails,vipulnsward/rails,illacceptanything/illacceptanything,illacceptanything/illacceptanything,utilum/rails,illacceptanything/illacceptanything,eileencodes/rails,travisofthenorth/rails,tjschuck/rails,kddeisz/rails,tgxworld/rails,flanger001/rails,Erol/rails,illacceptanything/illacceptanything,kddeisz/rails,MSP-Greg/rails,aditya-kapoor/rails,kirs/rails-1,odedniv/rails,jeremy/rails,palkan/rails,kaspth/rails,joonyou/rails,Stellenticket/rails,flanger001/rails,joonyou/rails,bogdanvlviv/rails,deraru/rails,utilum/rails,Vasfed/rails,pvalena/rails,utilum/rails,fabianoleittes/rails,rafaelfranca/omg-rails,EmmaB/rails-1,rafaelfranca/omg-rails,schuetzm/rails,arunagw/rails,illacceptanything/illacceptanything,alecspopa/rails,iainbeeston/rails,illacceptanything/illacceptanything,kamipo/rails,bogdanvlviv/rails,iainbeeston/rails,mechanicles/rails,starknx/rails,mathieujobin/reduced-rails-for-travis,jeremy/rails,flanger001/rails,kirs/rails-1,kamipo/rails,brchristian/rails,gfvcastro/rails,deraru/rails,printercu/rails,esparta/rails,ledestin/rails,gcourtemanche/rails,betesh/rails,brchristian/rails,georgeclaghorn/rails,Sen-Zhang/rails,shioyama/rails,lcreid/rails,yhirano55/rails,yahonda/rails,yalab/rails,EmmaB/rails-1,yhirano55/rails,Vasfed/rails,eileencodes/rails,mechanicles/rails,gcourtemanche/rails,vipulnsward/rails,mohitnatoo/rails,assain/rails,MSP-Greg/rails,Envek/rails,prathamesh-sonpatki/rails,BlakeWilliams/rails,yalab/rails,Stellenticket/rails,mathieujobin/reduced-rails-for-travis,repinel/rails,flanger001/rails,iainbeeston/rails,yalab/rails,mohitnatoo/rails,yawboakye/rails,travisofthenorth/rails,georgeclaghorn/rails,alecspopa/rails,illacceptanything/illacceptanything,tjschuck/rails,Edouard-chin/rails,felipecvo/rails,vipulnsward/rails,deraru/rails,kaspth/rails,MSP-Greg/rails,schuetzm/rails,schuetzm/rails,ledestin/rails,BlakeWilliams/rails,yhirano55/rails,mechanicles/rails,notapatch/rails,yahonda/rails,kmcphillips/rails,Stellenticket/rails,jeremy/rails,aditya-kapoor/rails,illacceptanything/illacceptanything,arunagw/rails,bogdanvlviv/rails