Updating README: build status & requirements

Author: ringods

README.md

@@ -1,17 +1,22 @@
-Terraform Provider
-==================
+Terraform Provider for Gitlab
+=============================
 
-- Website: https://www.terraform.io
+- [Documentation](https://www.terraform.io/docs/providers/gitlab/index.html)
 - [![Gitter chat](https://badges.gitter.im/hashicorp-terraform/Lobby.png)](https://gitter.im/hashicorp-terraform/Lobby)
 - Mailing list: [Google Groups](http://groups.google.com/group/terraform-tool)
+- Build status:
+  - ![Unit Tests](https://github.com/terraform-providers/terraform-provider-gitlab/workflows/Unit%20Tests/badge.svg)
+  - ![Acceptance Tests](https://github.com/terraform-providers/terraform-provider-gitlab/workflows/Acceptance%20Tests/badge.svg)
+  - ![Website Build](https://github.com/terraform-providers/terraform-provider-gitlab/workflows/Website%20Build/badge.svg)
+
 
 <img src="https://cdn.rawgit.com/hashicorp/terraform-website/master/content/source/assets/images/logo-hashicorp.svg" width="600px">
 
 Requirements
 ------------
 
--	[Terraform](https://www.terraform.io/downloads.html) 0.10.x
--	[Go](https://golang.org/doc/install) 1.11 (to build the provider plugin)
+-	[Terraform](https://www.terraform.io/downloads.html) 0.12.x
+-	[Go](https://golang.org/doc/install) 1.12 (to build the provider plugin)
 
 Building The Provider
 ---------------------