update minimum supported browsers
update minimum supported browsers

fixes #CNVS-12517

test-plan:
* with chrome 33 & 34, verify browser warning does not display
* with safari 6 & 7, verify browser warning does not display
* with firefox 27 & 28, verify browser warning does not display
* with internet explorer 10 & 11, verify browser warning does not display

Change-Id: I8a86dcef641c8c2b936097237e239320e6b0190c
Reviewed-on: https://gerrit.instructure.com/33493
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>
QA-Review: August Thornton <9adc7a1161ddf32ff608de792a7e50179545f026@instructure.com>
Product-Review: Bryan Madsen <0a3ba1af216659500dd8f41e29f3979f42452870@instructure.com>

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