turn off deprecated dynamic finders for rails 3 and rails 4
turn off deprecated dynamic finders for rails 3 and rails 4

closes CNVS-15126

note that find_by_* is not deprecated (but discouraged in
Canvas)

Change-Id: If6421cda0e2ebc48e59c45d07928ef43f586a12c
Reviewed-on: https://gerrit.instructure.com/42286
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Jacob Fugal <f862f167b85d41b225785c70d70808bc7337c1fe@instructure.com>
Product-Review: Cody Cutrer <c4fe2b1d90ef8f2548c8aeabfa633434316f0305@instructure.com>
QA-Review: Cody Cutrer <c4fe2b1d90ef8f2548c8aeabfa633434316f0305@instructure.com>

samuels410/greatlakes-lms,Rvor/canvas-lms,shidao-fm/canvas-lms,skmezanul/canvas-lms,whalejasmine/canvas-lms,utkarshx/canvas-lms,sdeleon28/canvas-lms,greyhwndz/canvas-lms,djbender/canvas-lms,wrdsb/canvas-lms,tgroshon/canvas-lms,sfu/canvas-lms,juoni/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,roxolan/canvas-lms,venturehive/canvas-lms,redconfetti/canvas-lms,utkarshx/canvas-lms,shidao-fm/canvas-lms,tgroshon/canvas-lms,juoni/canvas-lms,matematikk-mooc/canvas-lms,venturehive/canvas-lms,Rvor/canvas-lms,SwinburneOnline/canvas-lms,whalejasmine/canvas-lms,antoniuslin/canvas-lms,dgynn/canvas-lms,AndranikMarkosyan/lms,leftplusrightllc/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,efrj/canvas-lms,snehakachroo1/LSI_replica,sdeleon28/canvas-lms,whalejasmine/canvas-lms,djbender/canvas-lms,greyhwndz/canvas-lms,va7map/canvas-lms,fronteerio/canvas-lms,eCNAP/CANVAS,sdeleon28/canvas-lms,Jyaasa/canvas-lms,venturehive/canvas-lms,AndranikMarkosyan/lms,jay3126/canvas-lms,utkarshx/canvas-lms,jay3126/canvas-lms,sfu/canvas-lms,skmezanul/canvas-lms,redconfetti/canvas-lms,SwinburneOnline/canvas-lms,ShreniiNepal/shrenii_lmp,sfu/canvas-lms,eCNAP/CANVAS,Rvor/canvas-lms,dgynn/canvas-lms,roxolan/canvas-lms,Rvor/canvas-lms,samuels410/greatlakes-lms,fronteerio/canvas-lms,jay3126/canvas-lms,skmezanul/canvas-lms,matematikk-mooc/canvas-lms,leftplusrightllc/canvas-lms,snehakachroo1/LSI_replica,grahamb/canvas-lms,matematikk-mooc/canvas-lms,va7map/canvas-lms,snehakachroo1/LSI_replica,jay3126/canvas-lms,fronteerio/canvas-lms,samuels410/greatlakes-lms,samuels410/greatlakes-lms,kyroskoh/canvas-lms,narigone/canvas,leftplusrightllc/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,antoniuslin/canvas-lms,AndranikMarkosyan/lms,wrdsb/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,eCNAP/CANVAS,wrdsb/canvas-lms,narigone/canvas,HotChalk/canvas-lms,ShreniiNepal/shrenii_lmp,grahamb/canvas-lms,Jyaasa/canvas-lms,skmezanul/canvas-lms,snehakachroo1/LSI_replica,roxolan/canvas-lms,instructure/canvas-lms,AndranikMarkosyan/lms,djbender/canvas-lms,efrj/canvas-lms,Jyaasa/canvas-lms,whalejasmine/canvas-lms,matematikk-mooc/canvas-lms,va7map/canvas-lms,ShreniiNepal/shrenii_lmp,narigone/canvas,roxolan/canvas-lms,HotChalk/canvas-lms,sdeleon28/canvas-lms,juoni/canvas-lms,efrj/canvas-lms,wrdsb/canvas-lms,antoniuslin/canvas-lms,redconfetti/canvas-lms,juoni/canvas-lms,tgroshon/canvas-lms,kyroskoh/canvas-lms,instructure/canvas-lms,dgynn/canvas-lms,Jyaasa/canvas-lms,kyroskoh/canvas-lms,djbender/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,instructure/canvas-lms,utkarshx/canvas-lms,sfu/canvas-lms,HotChalk/canvas-lms,shidao-fm/canvas-lms,HotChalk/canvas-lms,va7map/canvas-lms,narigone/canvas,greyhwndz/canvas-lms,redconfetti/canvas-lms,eCNAP/CANVAS,efrj/canvas-lms,kyroskoh/canvas-lms,antoniuslin/canvas-lms,sfu/canvas-lms,ShreniiNepal/shrenii_lmp,greyhwndz/canvas-lms,dgynn/canvas-lms,fronteerio/canvas-lms,leftplusrightllc/canvas-lms,tgroshon/canvas-lms,shidao-fm/canvas-lms,grahamb/canvas-lms