Octorun JS Missing Enterprise Login Workaround

[StanleyGoldman]

Breakout of #617

• Implement missing enterprise workaround
  Removing Octokit #611 (comment)

As explained here, we need a specific status code to indicate that an enterprise user should utilize their password as a token.

Unity/src/GitHub.Api/Authentication/LoginManager.cs

Lines 254 to 265 in 0aa51f7

	bool EnterpriseWorkaround(UriString hostAddress, Exception e)
	{
	// Older Enterprise hosts either don't have the API end-point to PUT an authorization, or they
	// return 422 because they haven't white-listed our client ID. In that case, we just ignore
	// the failure, using basic authentication (with username and password) instead of trying
	// to get an authorization token.
	var apiException = e as ApiException;
	return !HostAddress.IsGitHubDotCom(hostAddress) &&
	(e is NotFoundException ||
	e is ForbiddenException ||
	apiException?.StatusCode == (HttpStatusCode)422);
	}