Update documentation for ELB SSL Certs Generation

[ranaskr]

The document README.md has no mention on installing AWS Command line tools to be able to run the upload_certs.sh (https://github.com/Accenture/adop-docker-compose/tree/master/provision/aws/ssl)

Please update the documentation to install AWS CLI from this portal before running uploading certs for ELB. Here is the URL https://aws.amazon.com/cli/

[RobertNorthard]

@ranaskr please can you make a PR to update the documentation?