allow configuring DJ's last ditch log file
allow configuring DJ's last ditch log file

fixes CNVS-12704

test plan:
 * script/delayed_job run should output to stdout as expected
 * script/delayed_job start should log rails startup to
   log/delayed_job.log
 * change config/delayed_jobs.yml to add
   last_ditch_logfile: log/dj.log under the 'development'
   or 'default' key (whichever you have)
 * restart jobs. rails startup should log to log/dj.log
 * change last_ditch_logfile to '| cat - > log/djcat.log'
   (with the quotes)
 * restart jobs. rails startup should log to log/djcat.log

Change-Id: I3b2e24605bc0e01aa6e5392be2b9a1ea6d88a331
Reviewed-on: https://gerrit.instructure.com/34260
Reviewed-by: Brian Palmer <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@instructure.com>
QA-Review: August Thornton <9adc7a1161ddf32ff608de792a7e50179545f026@instructure.com>
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Product-Review: Cody Cutrer <c4fe2b1d90ef8f2548c8aeabfa633434316f0305@instructure.com>

skmezanul/canvas-lms,Jyaasa/canvas-lms,Rvor/canvas-lms,redconfetti/canvas-lms,roxolan/canvas-lms,usmschuck/canvas,efrj/canvas-lms,HotChalk/canvas-lms,grahamb/canvas-lms,fronteerio/canvas-lms,matematikk-mooc/canvas-lms,sdeleon28/canvas-lms,matematikk-mooc/canvas-lms,antoniuslin/canvas-lms,narigone/canvas,wrdsb/canvas-lms,whalejasmine/canvas-lms,Unow/canvas-lms,snehakachroo1/LSI_replica,sfu/canvas-lms,utkarshx/canvas-lms,usmschuck/canvas,wye0220/shindig-canvas,efrj/canvas-lms,AndranikMarkosyan/lms,AndranikMarkosyan/lms,SwinburneOnline/canvas-lms,venturehive/canvas-lms,ShreniiNepal/shrenii_lmp,eCNAP/CANVAS,instructure/canvas-lms,ShreniiNepal/shrenii_lmp,Unow/canvas-lms,utkarshx/canvas-lms,skmezanul/canvas-lms,va7map/canvas-lms,leftplusrightllc/canvas-lms,wye0220/shindig-canvas,narigone/canvas,djbender/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,jay3126/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,Rvor/canvas-lms,eCNAP/CANVAS,snehakachroo1/LSI_replica,wye0220/shindig-canvas,tgroshon/canvas-lms,snehakachroo1/LSI_replica,grahamb/canvas-lms,samuels410/greatlakes-lms,greyhwndz/canvas-lms,SwinburneOnline/canvas-lms,kyroskoh/canvas-lms,usmschuck/canvas,SwinburneOnline/canvas-lms,fronteerio/canvas-lms,redconfetti/canvas-lms,greyhwndz/canvas-lms,sfu/canvas-lms,juoni/canvas-lms,tgroshon/canvas-lms,shidao-fm/canvas-lms,jay3126/canvas-lms,whalejasmine/canvas-lms,efrj/canvas-lms,samuels410/greatlakes-lms,antoniuslin/canvas-lms,tgroshon/canvas-lms,sdeleon28/canvas-lms,Rvor/canvas-lms,antoniuslin/canvas-lms,jay3126/canvas-lms,gbleydon/canvas-lms,leftplusrightllc/canvas-lms,juoni/canvas-lms,redconfetti/canvas-lms,juoni/canvas-lms,wrdsb/canvas-lms,fronteerio/canvas-lms,redconfetti/canvas-lms,AndranikMarkosyan/lms,gbleydon/canvas-lms,narigone/canvas,djbender/canvas-lms,dgynn/canvas-lms,venturehive/canvas-lms,antoniuslin/canvas-lms,kyroskoh/canvas-lms,grahamb/canvas-lms,matematikk-mooc/canvas-lms,sfu/canvas-lms,jay3126/canvas-lms,shidao-fm/canvas-lms,venturehive/canvas-lms,greyhwndz/canvas-lms,matematikk-mooc/canvas-lms,samuels410/greatlakes-lms,eCNAP/CANVAS,shidao-fm/canvas-lms,HotChalk/canvas-lms,Jyaasa/canvas-lms,utkarshx/canvas-lms,skmezanul/canvas-lms,whalejasmine/canvas-lms,instructure/canvas-lms,wrdsb/canvas-lms,venturehive/canvas-lms,kyroskoh/canvas-lms,Unow/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,HotChalk/canvas-lms,usmschuck/canvas,fronteerio/canvas-lms,sdeleon28/canvas-lms,va7map/canvas-lms,dgynn/canvas-lms,instructure/canvas-lms,Jyaasa/canvas-lms,juoni/canvas-lms,djbender/canvas-lms,Jyaasa/canvas-lms,sfu/canvas-lms,wrdsb/canvas-lms,sdeleon28/canvas-lms,djbender/canvas-lms,shidao-fm/canvas-lms,whalejasmine/canvas-lms,roxolan/canvas-lms,kyroskoh/canvas-lms,greyhwndz/canvas-lms,dgynn/canvas-lms,roxolan/canvas-lms,efrj/canvas-lms,skmezanul/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,grahamb/canvas-lms,SwinburneOnline/canvas-lms,utkarshx/canvas-lms,roxolan/canvas-lms,ShreniiNepal/shrenii_lmp,narigone/canvas,snehakachroo1/LSI_replica,Rvor/canvas-lms,gbleydon/canvas-lms,ShreniiNepal/shrenii_lmp,HotChalk/canvas-lms,leftplusrightllc/canvas-lms,instructure/canvas-lms,leftplusrightllc/canvas-lms,tgroshon/canvas-lms,va7map/canvas-lms,samuels410/greatlakes-lms,AndranikMarkosyan/lms,va7map/canvas-lms,eCNAP/CANVAS