increasing timeout for vpc now that we're creating an opsworks stack
put a small sleep just to make sure the opsworks groups are there
create a dummy opworks stack as part of the VPC. this will trigger the opsworks groups to be generated. without this, the jenkins stack will usually fail because by the time it goes to start the instances, the opsworks security groups don't exist yet. this isn't an ideal solution but the good ones (like not using opsworks SGs) aren't available via cloudformation.
updated readme