* add assume role with saml provider

* add assume role with saml provider, examples and readme

* add module for roles with SAML Identity Provider

* Added iam-group-with-assumable-roles-policy and iam-assumable-role

* Minor fixes

* add support to enable uploading public ssh key to IAM users

* make ssh key uploading an toggalable option

* Add details of ssh key managment to README

This allows the advertised variables to function.

The outputs had to be modified to work with conditionals in line with
the workaround in https://github.com/hashicorp/terraform/issues/17425.

* Added iam-account