Terraform creates subnets in different AZs
Terraform creates subnets in different AZs

fixes:
```
Error creating Application Load Balancer: InvalidConfigurationRequest: A load balancer cannot be attached to multiple subnets in the same Availability Zone
```

Signed-off-by: Brian Cunnie <bcunnie@pivotal.io>

[#135963933](https://www.pivotaltracker.com/story/show/135963933)

cloudfoundry-incubator/bosh-aws-cpi-release,cloudfoundry-incubator/bosh-aws-cpi-release,cloudfoundry-incubator/bosh-aws-cpi-release