Add 'google_organization' data source (hashicorp#887)

* Add 'google_organization' data source.

* Use 'GetResourceNameFromSelfLink'.

* Remove 'resourcemanager_helpers'.

* Use 'ConflictsWith' in schema.

* Add 'organization' argument and make 'name' an output-only attribute.

docs/d/google_organization.html.markdown

@@ -0,0 +1,43 @@
+---
+layout: "google"
+page_title: "Google: google_organization"
+sidebar_current: "docs-google-datasource-organization"
+description: |-
+  Get information about a Google Cloud Organization.
+---
+
+# google\_organization
+
+Use this data source to get information about a Google Cloud Organization.
+
+```hcl
+data "google_organization" "org" {
+  domain = "example.com"
+}
+
+resource "google_folder" "sales" {
+  display_name = "Sales"
+  parent       = "${data.google_organization.org.name}"
+}
+```
+
+## Argument Reference
+
+The arguments of this data source act as filters for querying the available Organizations.
+The given filters must match exactly one Organizations whose data will be exported as attributes.
+The following arguments are supported:
+
+* `organization` (Optional) - The name of the Organization in the form `{organization_id}` or `organizations/{organization_id}`.
+* `domain` (Optional) - The domain name of the Organization.
+
+~> **NOTE:** One of `organization` or `domain` must be specified.
+
+## Attributes Reference
+
+The following additional attributes are exported:
+
+* `id` - The Organization ID.
+* `name` - The resource name of the Organization in the form `organizations/{organization_id}`.
+* `directory_customer_id` - The Google for Work customer ID of the Organization.
+* `create_time` - Timestamp when the Organization was created. A timestamp in RFC3339 UTC "Zulu" format, accurate to nanoseconds. Example: "2014-10-02T15:01:23.045123456Z".
+* `lifecycle_state` - The Organization's current lifecycle state.

google.erb

@@ -64,6 +64,9 @@
       <li<%= sidebar_current("docs-google-kms-secret") %>>
       <a href="/docs/providers/google/d/google_kms_secret.html">google_kms_secret</a>
       </li>
+      <li<%= sidebar_current("docs-google-datasource-organization") %>>
+      <a href="/docs/providers/google/d/google_organization.html">google_organization</a>
+      </li>
       <li<%= sidebar_current("docs-google-datasource-signed_url") %>>
         <a href="/docs/providers/google/d/signed_url.html">google_storage_object_signed_url</a>
       </li>