bump gemspec for 0.5.4 release
bump gemspec for 0.5.4 release

pbrumm/whiskey_disk,openlogic/whisk,flogic/whiskey_disk,flogic/whiskey_disk,flogic/whiskey_disk,openlogic/whisk,kingandpartners/whiskey_disk,pbrumm/whiskey_disk,pbrumm/whiskey_disk,openlogic/whisk