Create necessary default instance profiles.

The first creation of an eb environment fails due to aws-elasticbeanstalk-ec2-role not being created (I had never created an environment via the console).

"The instance profile aws-elasticbeanstalk-ec2-role associated with the environment does not exist."

The current solution is creating this manually or creating an instance in aws console, which creates this profile. You can then re-run the eb create statement again. Should the cli create this profile automatically exactly as the console does?

Start with the `eb create` command path and inspect how the CLI handles the first environment creation and AWS instance-profile errors. Compare this with the profile created by the Elastic Beanstalk console. Done means a first environment creation no longer fails because `aws-elasticbeanstalk-ec2-role` is missing, with appropriate tests for the behavior.

Written by the indexing model from the issue text.