Dir.mkdir -> FileUtils.makedirs
Dir.mkdir -> FileUtils.makedirs

when creating a directory for a plugin symlink, the parent directory may
also not yet exist. use FileUtils.makedirs (behaves like mkdir -p)
instead of Dir.mkdir to ensure the full path is created as necessary.

Change-Id: Iafc00c945923c40613fffd9206a1e45ecb735cb6
Reviewed-on: https://gerrit.instructure.com/11915
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>

usmschuck/canvas,leftplusrightllc/canvas-lms,shidao-fm/canvas-lms,arrivu/qibla-ecampus,arrivu/qibla-ecampus,antoniuslin/canvas-lms,fronteerio/canvas-lms,arrivu/arrivu-lms,venturehive/canvas-lms,jay3126/canvas-lms,venturehive/canvas-lms,skmezanul/canvas-lms,wrdsb/canvas-lms,Rvor/canvas-lms,wrdsb/canvas-lms,tgroshon/canvas-lms,grahamb/canvas-lms,efrj/canvas-lms,leftplusrightllc/canvas-lms,ShreniiNepal/shrenii_lmp,fronteerio/canvas-lms,sdeleon28/canvas-lms,antoniuslin/canvas-lms,ShreniiNepal/shrenii_lmp,wrdsb/canvas-lms,grahamb/canvas-lms,tgroshon/canvas-lms,sfu/canvas-lms,jay3126/canvas-lms,wimemx/Canvas,HotChalk/canvas-lms,ShreniiNepal/shrenii_lmp,sdeleon28/canvas-lms,rup/Tarrax,Rvor/canvas-lms,utkarshx/canvas-lms,venturehive/canvas-lms,kyroskoh/canvas-lms,loganrun/pincan,Jyaasa/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,skmezanul/canvas-lms,samuels410/greatlakes-lms,samuels410/greatlakes-lms,juoni/canvas-lms,efrj/canvas-lms,rup/Tarrax,jay3126/canvas-lms,Jyaasa/canvas-lms,arrivu/hoodemo,Unow/canvas-lms,merichar/canvas-lms,greyhwndz/canvas-lms,efrj/canvas-lms,leftplusrightllc/canvas-lms,ankithbti/canvas_lms,fronteerio/canvas-lms,whalejasmine/canvas-lms,wimemx/Canvas,Jyaasa/canvas-lms,roxolan/canvas-lms,roxolan/canvas-lms,sdeleon28/canvas-lms,rup/Tarrax,arrivu/jigsaw-lms,landonwilkins/canvas-lms,efrj/canvas-lms,redconfetti/canvas-lms,landonwilkins/canvas-lms,usmschuck/canvas,merichar/canvas-lms,sfu/canvas-lms,va7map/canvas-lms,arrivu/hoodemo,antoniuslin/canvas-lms,arrivu/hoodemo,utkarshx/canvas-lms,sfu/canvas-lms,whalejasmine/canvas-lms,samuels410/greatlakes-lms,sdeleon28/canvas-lms,ankithbti/canvas_lms,SwinburneOnline/canvas-lms,djbender/canvas-lms,greyhwndz/canvas-lms,loganrun/pincan,Unow/canvas-lms,Unow/canvas-lms,whalejasmine/canvas-lms,arrivu/arrivu-lms,shidao-fm/canvas-lms,merichar/canvas-lms,antoniuslin/canvas-lms,HotChalk/canvas-lms,skmezanul/canvas-lms,wrdsb/canvas-lms,djbender/canvas-lms,arrivu/qibla-ecampus,kyroskoh/canvas-lms,va7map/canvas-lms,greyhwndz/canvas-lms,grahamb/canvas-lms,usmschuck/canvas,HotChalk/canvas-lms,utkarshx/canvas-lms,shidao-fm/canvas-lms,juoni/canvas-lms,loganrun/pincan,kyroskoh/canvas-lms,arrivu/arrivu-lms,wye0220/shindig-canvas,parbros/red-innovadores-lms,grahamb/canvas-lms,sfu/canvas-lms,utkarshx/canvas-lms,tgroshon/canvas-lms,redconfetti/canvas-lms,skmezanul/canvas-lms,va7map/canvas-lms,ShreniiNepal/shrenii_lmp,SwinburneOnline/canvas-lms,HotChalk/canvas-lms,nditech/red-innovadores-lms,redconfetti/canvas-lms,parbros/red-innovadores-lms,roxolan/canvas-lms,shidao-fm/canvas-lms,va7map/canvas-lms,fronteerio/canvas-lms,leftplusrightllc/canvas-lms,wye0220/shindig-canvas,arrivu/jigsaw-lms,Jyaasa/canvas-lms,SwinburneOnline/canvas-lms,juoni/canvas-lms,Unow/ins,whalejasmine/canvas-lms,SwinburneOnline/canvas-lms,nditech/red-innovadores-lms,kyroskoh/canvas-lms,grahamb/canvas-lms,juoni/canvas-lms,usmschuck/canvas,wye0220/shindig-canvas,greyhwndz/canvas-lms,landonwilkins/canvas-lms,nditech/red-innovadores-lms,ankithbti/canvas_lms,sli7246/canvas_branch,jay3126/canvas-lms,landonwilkins/canvas-lms,nditech/red-innovadores-lms,arrivu/jigsaw-lms,djbender/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,redconfetti/canvas-lms,sli7246/canvas_branch,Unow/ins,roxolan/canvas-lms,Unow/ins,sfu/canvas-lms,parbros/red-innovadores-lms,sli7246/canvas_branch,wimemx/Canvas,Rvor/canvas-lms,samuels410/greatlakes-lms,tgroshon/canvas-lms,Rvor/canvas-lms