add comment that vol from determine_volume is a hash
add comment that vol from determine_volume is a hash

bluekelp/aws,udomsak/aws,vervas/aws,joelmoss/aws,ubiquitousthey/aws,mediocregopher/aws,chef-cookbooks/aws,ellongrey/aws,custora/aws,joshuatobin/aws,BuyerQuest/aws,mdellanoce/aws,bdols/aws,zsiddique/aws,xacaxulu/aws,josephholsten/opscode-cookbooks-aws,yossigo/aws,ryansb/aws,americanhonors/chef-aws,AudaxHealthInc/aws-cookbook-public,strebitz/aws,paybyphone/aws,TheWeatherCompany/aws,needle-cookbooks/chef-opscode-aws,kriswallsmith/aws,manasg/aws,EverythingMe/aws,johnnyiller/aws,turtlebender/aws,rafaelfelix/aws,scalp42/aws,grosendorf/aws,dansteen/aws,Altiscale/aws,custora/aws,evertrue/aws,bazbremner/aws,adobejmong/aws,Xorlev/aws,simplyadrian/aws,ForeverOceans/aws,opscode-cookbooks/aws,cflynn07/aws,Tealium/aws,miketheman/aws-cookbook,arnaud036/aws,localytics/aws,apptentive-engineering/aws,incent-corp/aws,alexism/aws,joshoohaah/aws,itwasntandy/aws,zsol/aws,Nordstrom/aws,coupa-ops/aws,thomas-duffield/aws,uWhisp/aws,JeanMertz/aws