Always run `chef-client` via `ruby PATH/TO/chef-client` in tests.
Always run `chef-client` via `ruby PATH/TO/chef-client` in tests.

Fixes CHEF-4914

Running `chef-client` directly can result in a "system" `chef-client`
being run (e.g., an omnibus install of chef-client). When testing on
different ruby versions, this can cause segfaults because bundler sets
environment variables that cause C extension gems compiled against a
different ruby ABI to get loaded. For example, a JSON gem compiled
against ruby 1.9 can be loaded into ruby 2.0.

circleback/chef,docwhat/chef,adamleff/chef,Ppjet6/chef,skmichaelson/chef,zshuo/chef,cachamber/chef,paulmooring/chef,mwrock/chef,martinisoft/chef,strangelittlemonkey/chef,nvwls/chef,danielsdeleo/seth,jmhardison/chef,jagdeesh109/chef,martinb3/chef,MsysTechnologiesllc/chef,Igorshp/chef,youngjl1/chef,Tensibai/chef,nguyen-tien-mulodo/chef,docwhat/chef,renanvicente/chef,ekometti/chef,sysbot/chef,acaiafa/chef,nguyen-tien-mulodo/chef,youngjl1/chef,onlyhavecans/chef,youngjl1/chef,mikedodge04/chef,zuazo-forks/chef,nicklv/chef,joemiller/chef,polamjag/chef,robmul/chef,EasonYi/chef,jimmymccrory/chef,zuazo-forks/chef,skmichaelson/chef,b002368/chef-repo,malisettirammurthy/chef,jaymzh/chef,sempervictus/chef,skmichaelson/chef,Ppjet6/chef,Kast0rTr0y/chef,jagdeesh109/chef,ccsplit/chef,jblaine/chef,gsaslis/chef,jordane/chef,martinb3/chef,h4ck3rm1k3/chef,permyakovsv/chef,askl56/chef,askl56/chef,nalingarg2/chef-1,acaiafa/chef,higanworks/chef,ducthanh/chef,ranjib/chef,tomdoherty/chef,nellshamrell/chef,docwhat/chef,ekometti/chef,jaymzh/chef,EasonYi/chef,malisettirammurthy/chef,swalberg/chef,antonifs/chef,3dinfluence/chef,polamjag/chef,brettcave/chef,danielsdeleo/seth,pburkholder/chef,Kast0rTr0y/chef,sekrett/chef,nicklv/chef,joemiller/chef,circleback/chef,karthikrev/chef,askl56/chef,mio-g/chef,webframp/chef,b002368/chef-repo,AndyBoucher/Chef-Testing,Tensibai/chef,lamont-granquist/chef,ekometti/chef,jblaine/chef,pburkholder/chef,natewalck/chef,smurawski/chef,nathwill/chef,sempervictus/chef,swalberg/chef,onlyhavecans/chef,adamleff/chef,antonifs/chef,skmichaelson/chef,karthikrev/chef,criteo-forks/chef,MsysTechnologiesllc/chef,jk47/chef,h4ck3rm1k3/chef,renanvicente/chef,mikefaille/chef,higanworks/chef,patcon/chef,sekrett/chef,sempervictus/chef,andrewpsp/chef,EasonYi/chef,juliandunn/chef,askl56/chef,b002368/chef-repo,MsysTechnologiesllc/chef,jordane/chef,Tensibai/chef,faspl/chef,mal/chef,EasonYi/chef,ChaosCloud/chef,ckaushik/chef,strangelittlemonkey/chef,aaron-lane/chef,ccsplit/chef,legal90/chef,DeWaRs1206/chef,legal90/chef,jkerry/chef,erkolson/chef,cmluciano/chef,EasonYi/chef,smurawski/chef,sysbot/chef,nalingarg2/chef-1,nicklv/chef,mattray/chef,sometimesfood/chef,3dinfluence/chef,jaymzh/chef,mikedodge04/chef,mio-g/chef,bahamas10/chef,mio-g/chef,legal90/chef,jkerry/chef,nsdavidson/chef,sysbot/chef,someara/chef,tomdoherty/chef,sanditiffin/chef,permyakovsv/chef,lamont-granquist/chef,sanditiffin/chef,martinb3/chef,martinisoft/chef,zuazo-forks/chef,ktpan/chef-play,martinisoft/chef,sekrett/chef,kaznishi/chef,jimmymccrory/chef,renanvicente/chef,h4ck3rm1k3/chef,OpSitters/chef,gene1wood/chef,criteo-forks/chef,skmichaelson/chef,ktpan/chef-play,Igorshp/chef,mikefaille/chef,DeWaRs1206/chef,baberthal/chef,criteo-forks/chef,tomdoherty/chef,evan2645/chef,3dinfluence/chef,baberthal/chef,ccope/chef,nguyen-tien-mulodo/chef,martinb3/chef,ckaushik/chef,ckaushik/chef,swalberg/chef,BackSlasher/chef,jkerry/chef,cachamber/chef,erkolson/chef,ranjib/chef,swalberg/chef,joemiller/chef,evan2645/chef,nsdavidson/chef,nalingarg2/chef-1,custora/chef,natewalck/chef,Tensibai/chef,oclaussen/chef,3dinfluence/chef,gene1wood/chef,swalberg/chef,clintoncwolfe/chef,nsdavidson/chef,faspl/chef,gsaslis/chef,sometimesfood/chef,grubernaut/chef,Kast0rTr0y/chef,sometimesfood/chef,permyakovsv/chef,mwrock/chef,pburkholder/chef,antonifs/chef,legal90/chef,danielsdeleo/seth,jordane/chef,baberthal/chef,DeWaRs1206/chef,joemiller/chef,jimmymccrory/chef,cgvarela/chef,custora/chef,nsdavidson/chef,tbunnyman/chef,onlyhavecans/chef,someara/chef,cachamber/chef,sometimesfood/chef,mikedodge04/chef,mattray/chef,nalingarg2/chef-1,karthikrev/chef,higanworks/chef,karthikrev/chef,strangelittlemonkey/chef,MichaelPereira/chef,jimmymccrory/chef,karthikrev/chef,jblaine/chef,joemiller/chef,h4ck3rm1k3/chef,andrewpsp/chef,faspl/chef,gsaslis/chef,ranjib/chef,AndyBoucher/Chef-Testing,nicklv/chef,webframp/chef,aaron-lane/chef,aaron-lane/chef,jordane/chef,mikefaille/chef,jagdeesh109/chef,jk47/chef,oclaussen/chef,mio-g/chef,custora/chef,b002368/chef-repo,custora/chef,bahamas10/chef,grubernaut/chef,strangelittlemonkey/chef,custora/chef,andrewpsp/chef,someara/chef,smurawski/chef,nvwls/chef,tbunnyman/chef,zuazo-forks/chef,jonlives/chef,EasonYi/chef,cmluciano/chef,docwhat/chef,jk47/chef,jk47/chef,juliandunn/chef,nathwill/chef,juliandunn/chef,nalingarg2/chef-1,juliandunn/chef,mattray/chef,cmluciano/chef,b002368/chef-repo,robmul/chef,MichaelPereira/chef,ekometti/chef,BackSlasher/chef,Ppjet6/chef,pburkholder/chef,brettcave/chef,chef/chef,ccsplit/chef,danielsdeleo/seth,tomdoherty/chef,sanditiffin/chef,kaznishi/chef,tbriggs-curse/chef,nvwls/chef,adamleff/chef,jagdeesh109/chef,mal/chef,josb/chef,3dinfluence/chef,BackSlasher/chef,MichaelPereira/chef,ccsplit/chef,sideci-sample/sideci-sample-chef,ckaushik/chef,Kast0rTr0y/chef,nsdavidson/chef,natewalck/chef,mio-g/chef,faspl/chef,ChaosCloud/chef,erkolson/chef,circleback/chef,ktpan/chef-play,josb/chef,jonlives/chef,gene1wood/chef,cmluciano/chef,oclaussen/chef,zshuo/chef,sanditiffin/chef,webframp/chef,patcon/chef,andrewpsp/chef,kaznishi/chef,tas50/chef-1,jimmymccrory/chef,ranjib/chef,danielsdeleo/seth,jonlives/chef,circleback/chef,nguyen-tien-mulodo/chef,josb/chef,ranjib/chef,Ppjet6/chef,permyakovsv/chef,docwhat/chef,chef/chef,cgvarela/chef,zshuo/chef,jimmymccrory/chef,josb/chef,oclaussen/chef,adamleff/chef,grubernaut/chef,paulmooring/chef,polamjag/chef,evan2645/chef,ccsplit/chef,strangelittlemonkey/chef,gsaslis/chef,mal/chef,ckaushik/chef,DeWaRs1206/chef,sekrett/chef,ekometti/chef,BackSlasher/chef,erkolson/chef,robmul/chef,DeWaRs1206/chef,Igorshp/chef,baberthal/chef,sideci-sample/sideci-sample-chef,malisettirammurthy/chef,jkerry/chef,lamont-granquist/chef,mikedodge04/chef,OpSitters/chef,acaiafa/chef,AndyBoucher/Chef-Testing,jkerry/chef,antonifs/chef,webframp/chef,higanworks/chef,sempervictus/chef,martinb3/chef,jkerry/chef,tbunnyman/chef,permyakovsv/chef,ChaosCloud/chef,strangelittlemonkey/chef,faspl/chef,mal/chef,nathwill/chef,jagdeesh109/chef,cachamber/chef,mwrock/chef,joemiller/chef,mattray/chef,karthikrev/chef,lamont-granquist/chef,jonlives/chef,AndyBoucher/Chef-Testing,skmichaelson/chef,polamjag/chef,bahamas10/chef,sideci-sample/sideci-sample-chef,cachamber/chef,askl56/chef,brettcave/chef,chef/chef,mikedodge04/chef,josb/chef,tbriggs-curse/chef,josb/chef,mal/chef,acaiafa/chef,bahamas10/chef,juliandunn/chef,sometimesfood/chef,clintoncwolfe/chef,h4ck3rm1k3/chef,martinb3/chef,onlyhavecans/chef,clintoncwolfe/chef,patcon/chef,sempervictus/chef,mal/chef,baberthal/chef,jagdeesh109/chef,sideci-sample/sideci-sample-chef,kaznishi/chef,higanworks/chef,evan2645/chef,zuazo-forks/chef,nellshamrell/chef,someara/chef,youngjl1/chef,renanvicente/chef,jmhardison/chef,MichaelPereira/chef,DeWaRs1206/chef,b002368/chef-repo,ducthanh/chef,Tensibai/chef,jk47/chef,erkolson/chef,patcon/chef,someara/chef,youngjl1/chef,aaron-lane/chef,clintoncwolfe/chef,antonifs/chef,jk47/chef,sometimesfood/chef,oclaussen/chef,pburkholder/chef,webframp/chef,sempervictus/chef,brettcave/chef,malisettirammurthy/chef,antonifs/chef,tbunnyman/chef,aaron-lane/chef,OpSitters/chef,Igorshp/chef,nellshamrell/chef,sekrett/chef,docwhat/chef,tbriggs-curse/chef,zshuo/chef,criteo-forks/chef,Ppjet6/chef,nvwls/chef,MichaelPereira/chef,mikefaille/chef,jmhardison/chef,Igorshp/chef,sanditiffin/chef,jblaine/chef,gsaslis/chef,ducthanh/chef,cgvarela/chef,ktpan/chef-play,smurawski/chef,ktpan/chef-play,AndyBoucher/Chef-Testing,oclaussen/chef,nellshamrell/chef,renanvicente/chef,renanvicente/chef,BackSlasher/chef,gene1wood/chef,jblaine/chef,tbriggs-curse/chef,Igorshp/chef,pburkholder/chef,3dinfluence/chef,robmul/chef,ccope/chef,tas50/chef-1,cachamber/chef,sekrett/chef,tomdoherty/chef,nvwls/chef,ktpan/chef-play,chef/chef,kaznishi/chef,sysbot/chef,jonlives/chef,nicklv/chef,ccope/chef,adamleff/chef,tbunnyman/chef,ranjib/chef,Ppjet6/chef,faspl/chef,bahamas10/chef,acaiafa/chef,tbunnyman/chef,sysbot/chef,mikefaille/chef,jonlives/chef,acaiafa/chef,nathwill/chef,polamjag/chef,paulmooring/chef,natewalck/chef,legal90/chef,mattray/chef,tbriggs-curse/chef,tas50/chef-1,sanditiffin/chef,jaymzh/chef,sideci-sample/sideci-sample-chef,OpSitters/chef,grubernaut/chef,circleback/chef,BackSlasher/chef,andrewpsp/chef,nguyen-tien-mulodo/chef,natewalck/chef,robmul/chef,legal90/chef,ckaushik/chef,brettcave/chef,h4ck3rm1k3/chef,ekometti/chef,circleback/chef,patcon/chef,nathwill/chef,martinisoft/chef,OpSitters/chef,patcon/chef,jmhardison/chef,paulmooring/chef,nellshamrell/chef,evan2645/chef,someara/chef,cgvarela/chef,ducthanh/chef,aaron-lane/chef,nellshamrell/chef,zuazo-forks/chef,ChaosCloud/chef,AndyBoucher/Chef-Testing,Kast0rTr0y/chef,martinisoft/chef,jordane/chef,mio-g/chef,swalberg/chef,tbriggs-curse/chef,webframp/chef,paulmooring/chef,robmul/chef,polamjag/chef,grubernaut/chef,nathwill/chef,zshuo/chef,malisettirammurthy/chef,MichaelPereira/chef,clintoncwolfe/chef,ccsplit/chef,evan2645/chef,OpSitters/chef,erkolson/chef,gsaslis/chef,ccope/chef,youngjl1/chef,grubernaut/chef,malisettirammurthy/chef,nvwls/chef,Kast0rTr0y/chef,MsysTechnologiesllc/chef,criteo-forks/chef,cgvarela/chef,zshuo/chef,brettcave/chef,smurawski/chef,lamont-granquist/chef,bahamas10/chef,onlyhavecans/chef,onlyhavecans/chef,smurawski/chef,permyakovsv/chef,criteo-forks/chef,baberthal/chef,lamont-granquist/chef,ChaosCloud/chef,clintoncwolfe/chef,ducthanh/chef,ducthanh/chef,paulmooring/chef,cgvarela/chef,adamleff/chef,mwrock/chef,askl56/chef,mikefaille/chef,nsdavidson/chef,jblaine/chef,nalingarg2/chef-1,kaznishi/chef,tas50/chef-1,ccope/chef,andrewpsp/chef,cmluciano/chef,jmhardison/chef,custora/chef,nicklv/chef,natewalck/chef,jmhardison/chef,ChaosCloud/chef,mikedodge04/chef,nguyen-tien-mulodo/chef