Revert type from object to map
Revert type from object to map

This commit reverts the type for the enforcer_instance_access_config
variable from object() to map() as requested from PR #202
https://github.com/forseti-security/terraform-google-forseti/pull/202

In using map() instead of object(), Terraform no longer requires
specific keys according to a schema and instead will pass the map
wholesale through to the module code.

forseti-security/terraform-google-forseti,forseti-security/terraform-google-forseti,forseti-security/terraform-google-forseti