Add failing vpc elastic ip test
Route53 Record.set_alias was broken by the addition of target
health evaluation.  Fix this and add tests for the new usage
and original usage.  Include health evaluation status in to_print.
Fix route53 alias to_print and change default health eval to False
Add allocation id check & reassociation kwarg to address associate method
Prefer allocation id and association id over public ip
Add unit tests to cover new connection arguments and allocation id preference
Update integration tests to properly tear down VPC
Altered the pip install for Travis.
Merge remote-tracking branch 'leetrout/fix/eip-association' into develop

Fixes #2131, #1310.
Merge pull request #2126 from jimbrowne/route53-alias-healthcheck-fix

Fix Route53 aliases, which were broken by the addition of health checks. Fixes #2162.