Fix link to iam-assumable-role example in README (#35)

iam-assumable-role example link was pointing to iam-assumable-roles

README.md

@@ -231,7 +231,7 @@ Use [iam-policy module](https://github.com/terraform-aws-modules/terraform-aws-i
 
 * [complete](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/modules/complete) - Create all required resources to allow one group of users to assume privileged role, while another group of users can only assume readonly role.
 * [iam-account](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/examples/iam-account) - Set AWS account alias and password policy
-* [iam-assumable-role](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/examples/iam-assumable-roles) - Create individual IAM role which can be assumed from specified ARNs (AWS accounts, IAM users, etc)
+* [iam-assumable-role](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/examples/iam-assumable-role) - Create individual IAM role which can be assumed from specified ARNs (AWS accounts, IAM users, etc)
 * [iam-assumable-roles](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/examples/iam-assumable-roles) - Create several IAM roles which can be assumed from specified ARNs (AWS accounts, IAM users, etc)
 * [iam-assumable-roles-with-saml](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/examples/iam-assumable-roles-with-saml) - Create several IAM roles which can be assumed by users with a SAML Identity Provider
 * [iam-group-with-assumable-roles-policy](https://github.com/terraform-aws-modules/terraform-aws-iam/tree/master/examples/iam-group-with-assumable-roles-policy) - IAM group with users who are allowed to assume IAM roles in the same or in separate AWS account