Support using AWS IAM Roles
Change config value to roles(plural)
Merge branch 'iam-roles' of github.com:danielfarrell/asset_sync into danielfarrell-iam-roles

* 'iam-roles' of github.com:danielfarrell/asset_sync:
  Change config value to roles(plural)
  Support using AWS IAM Roles
Merge branch 'danielfarrell-iam-roles'

* danielfarrell-iam-roles:
  Change config value to roles(plural)
  Support using AWS IAM Roles