rkt: Split some code in test to separate functions
rkt: Split some code in test to separate functions

Will be used by docker auth unit tests.

iaguis/rkt,nhlfr/rkt,intelsdi-x/rkt,dalanlan/rkt,matthaias/rkt,bsmr-go/rkt,wparad/rkt,rhvgoyal/rkt,dgonyeo/rkt,endocode/rkt,sinfomicien/rkt,s-urbaniak/rkt,squeed/rkt,lucasallan/rkt,yifan-gu/rocket,jzelinskie/rkt,il9ue/rkt,Yhgenomics/rkt,s-urbaniak/rkt,rot26/rkt,kinvolk/rkt,Shashwatsh/rkt,mjg59/rkt,monstermunchkin/rkt,iankronquist/rkt,Shashwatsh/rkt,euank/rkt,dalanlan/rkt,nhlfr/rkt,cab105/rkt,krnowak/rkt,joshix/rkt,MattDees/rkt,mattthias/pkg-rkt,MabinGo/rkt,rot26/rkt,joshix/rkt,krnowak/rkt,MabinGo/rkt,crawford/rkt,coreos/rkt,alban/rkt,tv42/rkt,fdserr/rkt,ChengTiesheng/rkt,michelangelo13/rkt,tixxdz/rkt,mattthias/pkg-rkt,jjlakis/rkt,jasonchaffee/rkt,liugenping/rkt,MattDees/rkt,adfernandes/rkt,shtouff/rkt,Wilybald/rkt,marineam/rkt,lee212/rkt,yifan-gu/rocket,adfernandes/rkt,shobhit85/rkt,coreos/rkt,endocode/rkt,tmrts/rkt,maquanyi/rkt,krnowak/rkt,yifan-gu/rocket,wparad/rkt,shobhit85/rkt,crawford/rkt,jjlakis/rkt,chrisseto/rkt,intelsdi-x/rkt,ybubnov/rkt,xnox/rkt,fdserr/rkt,iaguis/rkt,luebken/rkt,shobhit85/rkt,liugenping/rkt,ybubnov/rkt,alban/rkt,Wilybald/rkt,mike1729/rkt,lee212/rkt,liubq919/rkt,achanda/rkt,xnox/rkt,kinvolk/rkt,sstabellini/rkt,alexhersh/rkt,jzelinskie/rkt,Yhgenomics/rkt,lucasallan/rkt,klizhentas/rkt,matthaias/rkt,MattDees/rkt,akshaykarle/rkt,MabinGo/rkt,clearlinux/rkt,wparad/rkt,shtouff/rkt,jakon89/rkt,marineam/rkt,sgotti/rkt,linki/rkt,iaguis/rkt,linki/rkt,sgotti/rkt,matthaias/rkt,mjg59/rkt,Shashwatsh/rkt,bsmr-go/rkt,squaremo/rkt,fdserr/rkt,maquanyi/rkt,kbrwn/rkt,yifan-gu/rkt,cab105/rkt,Wilybald/rkt,jasonchaffee/rkt,squeed/rkt,monstermunchkin/rkt,iankronquist/rkt,markllama/rkt,smarvin/rkt,tmrts/rkt,il9ue/rkt,akshaykarle/rkt,iankronquist/rkt,rkt/rkt,chrisseto/rkt,bsmr-go/rkt,tixxdz/rkt,euank/rkt,lucasallan/rkt,blixtra/rkt,blixtra/rkt,intfrr/rkt,intfrr/rkt,jakon89/rkt,mattthias/pkg-rkt,shtouff/rkt,klizhentas/rkt,sinfomicien/rkt,smarvin/rkt,joshix/rkt,s-urbaniak/rkt,yifan-gu/rkt,squeed/rkt,markllama/rkt,rkt/rkt,nhlfr/rkt,jzelinskie/rkt,intfrr/rkt,mike1729/rkt,smarvin/rkt,lee212/rkt,tv42/rkt,rhvgoyal/rkt,dgonyeo/rkt,jasonchaffee/rkt,jonboulle/rkt,rkt/rkt,sgotti/rkt,kinvolk/rkt,euank/rkt,achanda/rkt,jonboulle/rkt,michelangelo13/rkt,chrisseto/rkt,lucasallan/rkt,liugenping/rkt,jakon89/rkt,akshaykarle/rkt,clearlinux/rkt,tv42/rkt,blixtra/rkt,markllama/rkt,marineam/rkt,ChengTiesheng/rkt,coreos/rkt,kinvolk/rkt,xnox/rkt,intelsdi-x/rkt,crawford/rkt,luebken/rkt,luebken/rkt,rkt/rkt,alexhersh/rkt,ChengTiesheng/rkt,monstermunchkin/rkt,cab105/rkt,klizhentas/rkt,il9ue/rkt,alban/rkt,liubq919/rkt,jjlakis/rkt,endocode/rkt,Yhgenomics/rkt,dalanlan/rkt,achanda/rkt,clearlinux/rkt,alexhersh/rkt,ybubnov/rkt,sstabellini/rkt,liubq919/rkt,rhvgoyal/rkt,tixxdz/rkt,sinfomicien/rkt,linki/rkt,squaremo/rkt,mjg59/rkt,sstabellini/rkt,jonboulle/rkt,Wilybald/rkt,michelangelo13/rkt,dgonyeo/rkt,mike1729/rkt,kbrwn/rkt,squaremo/rkt,rot26/rkt,maquanyi/rkt,adfernandes/rkt,yifan-gu/rkt,tmrts/rkt,joshix/rkt,kbrwn/rkt