Bump ffi version to something compatible with chef.
Bump ffi version to something compatible with chef.

mattray/ohai,numericillustration/ohai,acaiafa/ohai,higanworks/ohai,bougyman/ohai,375gnu/ohai,adamleff/ohai,cmluciano/ohai,tas50/ohai-1,johnbellone/ohai,zshuo/ohai,davide125/ohai,davide125/ohai,numericillustration/ohai,Juniper/ohai,jbfavre/ohai,mattray/ohai,jaymzh/ohai,tas50/ohai-1,sh9189/ohai,higanworks/ohai,phreakocious/ohai,shtzr840329/ohai,bougyman/ohai,Fodoj/ohai,zshuo/ohai,Juniper/ohai,375gnu/ohai,juliandunn/ohai,jbfavre/ohai,johnbellone/ohai,criteo-forks/ohai,btm/ohai,chef/ohai,http-418/ohai,shtzr840329/ohai,juliandunn/ohai,http-418/ohai,glennmatthews/ohai,chef/ohai,dreamnite/ohai,adamleff/ohai,n-marton/ohai,nathwill/ohai,jseely/ohai,btm/ohai,glennmatthews/ohai,n-marton/ohai,sh9189/ohai,Fodoj/ohai,nathwill/ohai,cmluciano/ohai,criteo-forks/ohai,acaiafa/ohai,jaymzh/ohai,jseely/ohai,dreamnite/ohai,phreakocious/ohai