Clean up elb_loadbalancer tests
Clean up elb_loadbalancer tests

There was both duplication (instead of reusing a common ec2_instance) and
missing tests (idempotency).

zleswomp/puppetlabs-aws,marksyme/puppetlabs-aws,DavidS/puppetlabs-aws,rfletcher/puppet-aws,benpillet/puppetlabs-aws,hundredacres/puppetlabs-aws,zvymazal/puppetlabs-aws,marksyme/puppetlabs-aws,puppetlabs/puppetlabs-aws,DavidS/puppetlabs-aws,hundredacres/puppetlabs-aws,zvymazal/puppetlabs-aws,daveseff/puppetlabs-aws,zleswomp/puppetlabs-aws,puppetlabs/puppetlabs-aws,benpillet/puppetlabs-aws,rfletcher/puppet-aws,gregohardy/puppetlabs-aws,daveseff/puppetlabs-aws,gregohardy/puppetlabs-aws