Added OpenStack::Server#created and #updated
Added OpenStack::Server#created and #updated

My OpenStack compute environment returns these two fields in the
response from get_server_details.  This commit exposes them in the
Server objects.

alphagov/fog,nandhanurrevanth/fog,sferik/fog,nicolasbrechet/fog,displague/fog,mavenlink/fog,yyuu/fog,asebastian-r7/fog,b0ric/fog,yyuu/fog,pyama86/fog,seanhandley/fog,glennpratt/fog,sideci-sample/sideci-sample-fog,phillbaker/fog,dhague/fog,plribeiro3000/fog,zephyrean/fog,10io/fog,martinb3/fog,nalabjp/fog,glennpratt/fog,kongslund/fog,kongslund/fog,10io/fog,mitchlloyd/fog,zephyrean/fog,fog/fog,nalabjp/fog,pravi/fog,covario-cdiaz/fog,bryanl/fog,theforeman/fog,ManageIQ/fog,asebastian-r7/fog,cocktail-io/fog,sideci-sample/sideci-sample-fog,icco/fog,dtdream/fog,nandhanurrevanth/fog,adamleff/fog,brandondunne/fog,dustacio/fog,duhast/fog,eLobato/fog,papedaniel/fog,pravi/fog,TerryHowe/fog,phillbaker/fog,plribeiro3000/fog,brilliomsinterop/fog,mohitsethi/fog,ManageIQ/fog,nandhanurrevanth/fog,MSOpenTech/fog,NETWAYS/fog,mavenlink/fog,displague/fog,phillbaker/fog,backupify/fog,runtimerevolution/fog,papedaniel/fog,theforeman/fog,ack/fog,unorthodoxgeek/fog,nicolasbrechet/fog,eLobato/fog,mohitsethi/fog,Programatica/fog,github/fog,joshisa/fog,brilliomsinterop/fog,brilliomsinterop/fog,sapcc/fog,b0e/fog,dtdream/fog,rackspace/fog,dLobatog/fog,petems/fog,bryanl/fog,github/fog,runtimerevolution/fog,zephyrean/fog,sapcc/fog,surminus/fog,martinb3/fog,fog/fog,cocktail-io/fog,Programatica/fog,lwander/fog,Ladas/fog,duhast/fog,SpryBTS/fog,joshmyers/fog,Ladas/fog,adecarolis/fog,pyama86/fog,ack/fog,petems/fog,unorthodoxgeek/fog,NETWAYS/fog,adecarolis/fog,b0ric/fog,adamleff/fog,12spokes/fog,TerryHowe/fog,covario-cdiaz/fog,surminus/fog,dhague/fog,icco/fog,MSOpenTech/fog,SpryBTS/fog,dLobatog/fog,joshmyers/fog,dustacio/fog,rackspace/fog,alphagov/fog,seanhandley/fog,lwander/fog,mitchlloyd/fog,joshisa/fog,backupify/fog,bdunne/fog,dpowell7/fog