r/resource_aws_eip: implement retry reading EIPs
r/resource_aws_eip: implement retry reading EIPs

Fixes https://github.com/coreos/tectonic-installer/issues/1246

nbaztec/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,nbaztec/terraform-provider-aws,kjmkznr/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,ashinohara/terraform-provider-aws,terraform-providers/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,Ninir/terraform-provider-aws,Ninir/terraform-provider-aws,Ninir/terraform-provider-aws,kjmkznr/terraform-provider-aws,ClementCunin/terraform-provider-aws,terraform-providers/terraform-provider-aws,nbaztec/terraform-provider-aws,nbaztec/terraform-provider-aws,terraform-providers/terraform-provider-aws,ClementCunin/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,ClementCunin/terraform-provider-aws,ashinohara/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,Ninir/terraform-provider-aws,ClementCunin/terraform-provider-aws,ashinohara/terraform-provider-aws,ashinohara/terraform-provider-aws