Add visibility parameter to repository resource

Adds the additional visibility parameter allowing for enterprise
accounts to set the repository to be only internally visible.

The endpoint is a little sketchy:
* an error if trying to update with a visibility value that is the same
* auth issues are encountered if trying to create with a visibility
  value. The parameter needs to be ignored during create, and updated
  subsequently.

Resolves integrations#304

github/resource_github_repository.go

@@ -41,8 +41,17 @@ func resourceGithubRepository() *schema.Resource {
 				Optional: true,
 			},
 			"private": {
-				Type:     schema.TypeBool,
-				Optional: true,
+				Type:          schema.TypeBool,
+				Computed:      true, // is affected by "visibility"
+				Optional:      true,
+				ConflictsWith: []string{"visibility"},
+				Deprecated:    "use visibility instead",
+			},
+			"visibility": {
+				Type:         schema.TypeString,
+				Optional:     true,
+				Computed:     true, // is affected by "private"
+				ValidateFunc: validation.StringInSlice([]string{"public", "private", "internal"}, false),
 			},
 			"has_issues": {
 				Type:     schema.TypeBool,
@@ -179,6 +188,7 @@ func resourceGithubRepositoryObject(d *schema.ResourceData) *github.Repository {
 		Description:         github.String(d.Get("description").(string)),
 		Homepage:            github.String(d.Get("homepage_url").(string)),
 		Private:             github.Bool(d.Get("private").(bool)),
+		Visibility:          github.String(d.Get("visibility").(string)),
 		HasDownloads:        github.Bool(d.Get("has_downloads").(bool)),
 		HasIssues:           github.Bool(d.Get("has_issues").(bool)),
 		HasProjects:         github.Bool(d.Get("has_projects").(bool)),
@@ -209,6 +219,12 @@ func resourceGithubRepositoryCreate(d *schema.ResourceData, meta interface{}) er
 	}
 
 	repoReq := resourceGithubRepositoryObject(d)
+
+	// Auth issues (403 You need admin access to the organization before adding a repository to it.)
+	// are encountered when the resources is created with the visibility parameter. As
+	// resourceGithubRepositoryUpdate is called immediately after, this is subsequently corrected.
+	repoReq.Visibility = nil
+
 	orgName := meta.(*Organization).name
 	repoName := repoReq.GetName()
 	ctx := context.Background()
@@ -303,6 +319,7 @@ func resourceGithubRepositoryRead(d *schema.ResourceData, meta interface{}) erro
 	d.Set("description", repo.GetDescription())
 	d.Set("homepage_url", repo.GetHomepage())
 	d.Set("private", repo.GetPrivate())
+	d.Set("visibility", repo.GetVisibility())
 	d.Set("has_issues", repo.GetHasIssues())
 	d.Set("has_projects", repo.GetHasProjects())
 	d.Set("has_wiki", repo.GetHasWiki())
@@ -346,6 +363,12 @@ func resourceGithubRepositoryUpdate(d *schema.ResourceData, meta interface{}) er
 	client := meta.(*Organization).v3client
 
 	repoReq := resourceGithubRepositoryObject(d)
+
+	// The endpoint will throw an error if trying to PATCH with a visibility value that is the same
+	if !d.HasChange("visibility") {
+		repoReq.Visibility = nil
+	}
+
 	// Can only set `default_branch` on an already created repository with the target branches ref already in-place
 	if v, ok := d.GetOk("default_branch"); ok {
 		branch := v.(string)

github/resource_github_repository_test.go

@@ -562,6 +562,7 @@ type testAccGithubRepositoryExpectedAttributes struct {
 	Description         string
 	Homepage            string
 	Private             bool
+	Visibility          string
 	HasDownloads        bool
 	HasIssues           bool
 	HasProjects         bool
@@ -594,6 +595,9 @@ func testAccCheckGithubRepositoryAttributes(repo *github.Repository, want *testA
 		if private := repo.GetPrivate(); private != want.Private {
 			return fmt.Errorf("got private %#v; want %#v", private, want.Private)
 		}
+		if visibility := repo.GetVisibility(); visibility != want.Visibility {
+			return fmt.Errorf("got visibility %#v; want %#v", visibility, want.Visibility)
+		}
 		if hasIssues := repo.GetHasIssues(); hasIssues != want.HasIssues {
 			return fmt.Errorf("got has issues %#v; want %#v", hasIssues, want.HasIssues)
 		}

website/docs/r/repository.html.markdown

@@ -41,6 +41,10 @@ The following arguments are supported:
 
 * `private` - (Optional) Set to `true` to create a private repository.
   Repositories are created as public (e.g. open source) by default.
+
+* `visibility` - (Optional) Can be `public` or `private`. If your organization is associated with an enterprise account 
+using GitHub Enterprise Cloud or GitHub Enterprise Server 2.20+, visibility can also be `internal`. The `visibility` 
+parameter overrides the `private` parameter.
 
 * `has_issues` - (Optional) Set to `true` to enable the GitHub Issues features
   on the repository.