[semver:minor] Add new param for skip aws setup:

[cesarcelism]

Add optional aws-cli setup

Reported Issue #29

• Add a flag to install-aws-cli. When you're using profiles configuration for aws-cli this orb overrides the setup making it useless. This flag helps to skip the aws-setup to use the defined at the working pipeline
• Added example of how to use this flag.

[pinglamb]

According to the other "official" orb aws-eks, the parameter is named: install-aws-cli: https://github.com/CircleCI-Public/aws-eks-orb/blob/master/src/commands/update-kubeconfig-with-authenticator.yml#L70

[cesarcelism]

PR updated: rename skip flag to install-aws-cli

[brivu]

Hey @cesarcelism,

I am doing a rewrite of this orb and have included this feature in PR #36. Thanks for you contribution!

Best, Brian