 	return "\(identifier)/\(version)"
 }()
 
+/// The type of content to request from the GitHub API.
+private let APIContentType = "application/vnd.github.v3+json"
+
 /// Describes a GitHub.com repository.
 public struct GitHubRepository: Equatable {
 	public let owner: String


	return request
}

/// with the given credentials.
internal func createGitHubRequest(URL: NSURL, credentials: GitHubCredentials?) -> NSURLRequest {
	let request = NSMutableURLRequest(URL: URL)
	request.setValue(APIContentType, forHTTPHeaderField: "Accept")
	request.setValue(userAgent, forHTTPHeaderField: "User-Agent")

	if let credentials = credentials {
