nvm_remote_version: add unit tests
nvm_remote_version: add unit tests

`nvm_ls_remote` is stubbed out to avoid making network calls here.
kumaria/nvm,scq000/nvm,jaawerth/nvm,egilkh/nvm,thomasf/nvm,PeterDaveHello/nvm,woss/nvm,icyflame/nvm,jhliberty/nvm,nontage24/nvm,misterdjules/nvm,mmorejon/nvm,Ingelheim/nvm,chinazhaghai/nvm,DigitallySeamless/nvm,WY08271/nvm,mmorejon/nvm,pmq20/nvm,Richardphp/nvm,evocateur/nvm,sjfkai/nvm,cnpm/nvm,edwmurph/nvm,wahyutaufik/nvm,JanChw/nvm,hkdobrev/nvm,mirydz/nvm,evocateur/nvm,michael-ni/nvm,gtdeng/nvm,domenicosolazzo/nvm,jaawerth/nvm,Salahudeen/nvm,chinazhaghai/nvm,cjac/nvm,CristianCantoro/nvm,tlevine/nvm,modulexcite/nvm,cirosantilli/nvm,bevacqua/nvm,youleiy/nvm,Kuzirashi/nvm,thomasf/nvm,SampleLiao/nvm,creationix/nvm,cirosantilli/nvm,nontage24/nvm,creationix/nvm,elrasguno/nvm,SampleLiao/nvm,wskplho/nvm,devedbox/nvm,PeterDaveHelloKitchen/nvm,Theodeus/nvm,IonicaBizauKitchen/nvm,hkdobrev/nvm,kmctown/nvm,Salahudeen/nvm,jbergstroem/nvm,psychoss/nvm,elrasguno/nvm,gtdeng/nvm,owen-it/nvm,Theodeus/nvm,diegofcb10/nvm,slariviere/nvm,cnpm/nvm,bbuck/nvm,Richardphp/nvm,slariviere/nvm,hanhailong/nvm,NicCollins/nvm,kmctown/nvm,misterdjules/nvm,christophercaburog/nvm,DigitallySeamless/nvm,dfackler/nvm,edwmurph/nvm,WY08271/nvm,greyhwndz/nvm,JanChw/nvm,williamboman/nvm,egilkh/nvm,tianzhihen/nvm,mirydz/nvm,modulexcite/nvm,reybango/nvm,parasaro92/nvm,domenicosolazzo/nvm,joneit/nvm,williamboman/nvm,tianzhihen/nvm,IonicaBizauKitchen/nvm,psychoss/nvm,jbergstroem/nvm,fnogatz/swivm,scq000/nvm,bbuck/nvm,parasaro92/nvm,ljharb/nvm,JasonChrYoung/nvm,CristianCantoro/nvm,hanhailong/nvm,owen-it/nvm,michael-ni/nvm,JasonChrYoung/nvm,wahyutaufik/nvm,pmq20/nvm,joneit/nvm,lukechilds/nvm,Ingelheim/nvm,diegofcb10/nvm,PeterDaveHello/nvm,vinaykaradia/clone-nvm,ljharb/nvm,dfackler/nvm,LeeLovCY/nvm,greyhwndz/nvm,lukechilds/nvm,kumaria/nvm,christophercaburog/nvm,icyflame/nvm,tlevine/nvm,reybango/nvm,LeeLovCY/nvm,vinaykaradia/clone-nvm,PeterDaveHelloKitchen/nvm,jhliberty/nvm,Kuzirashi/nvm,woss/nvm,devedbox/nvm,youleiy/nvm,cjac/nvm,bevacqua/nvm,wskplho/nvm