Change default ELB security policy to ELBSecurityPolicy-TLS-1-2-2017-01.
Change default ELB security policy to ELBSecurityPolicy-TLS-1-2-2017-01.

To make the ELB traffic more secure we want to remove support for TLSv1 and TLSv1.1.

The ELBSecurityPolicy-TLS-1-2-2017-01 additionally disables the following SSL ciphers:
 - ECDHE-ECDSA-AES128-SHA
 - ECDHE-ECDSA-AES256-SHA
 - ECDHE-RSA-AES128-SHA
 - ECDHE-RSA-AES256-SHA
 - AES128-SHA
 - AES256-SHA

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf