Make service plans public on cf_service_access

[psycofdj]

When creating a service-broker, service plans are private by default (ie: "public" : false attribute of /v2/service_plans, which make the service invisible in the marketplace).

The PR propose to add the optional public attribute to the cf_service_access resource. This attribute controls whenever the associated plan should be set public or private. It conflicts with org attribute that
controls per-org access.

Resource

resource "cf_service_access" "org1-mysql-512mb" {
     plan = "${cf_service_broker.mysql.service_plans["p-mysql/512mb"]}"
     public = true
}

resource "cf_service_access" "org1-mysql-512mb" {
    plan = "${cf_service_broker.mysql.service_plans["p-mysql/1gb"]}"
    org = "${cf_org.org1.id}"
}

Argument reference:

• plan - (Required) The ID of the service plan to grant access to
• org - (Optional) The ID of the Org which should have access to the plan. Conflicts with public.
• public - (Optional) Boolean that controls the public state of the plan. Conflicts with org.

Import

Import syntax is unchanged but its behavior is modified.

$ terraform import cf_service_access.org1-mysql-512mb a-guid

If given id matches existing service_plan_visibilities, resource will be imported as a service_access targeting an organization. Otherwise, it will be imported as service_access controlling plan's public state.

[gberche-orange]

@psycofdj

I'd suggest the following clarification to doc:

If the given `id` matches [a service plan id](http://apidocs.cloudfoundry.org/280/service_plans/updating_a_service_plan.html), then the resource will be imported as `service_access` controlling plan's public state.

Otherwise, the import would fail

[gberche-orange]

@mevansam I wonder background rationale for naming this resource cf_service_access w.r.t. cf_service_plan_access (since it manages access to individual service plan and not access to service definition) ? Maybe something to discuss prior to cutting 1.0 release.

[mevansam]

I concur with @gberche-orange on renaming this resource to cf_service_plan_access. Should we make the change within this same pull request or create a new pull request? Other than that change look good pending update to documentation as per @gberche-orange 's review comment.