Interface detection does not ignore namespaces, phpdoc, use, etc.

[sirbrillig]

The interface detection in RequireStrictTypesSniff (isFileOnlyAnInterface()) should ignore harmless top-level tokens like namespaces, phpdoc lines, use expressions, etc.

Discovered in #20

[Chrico]

Howdy! The fix for #20 seems to work now, but it introduces a new error. This message comes from the TypeHintSniff:

19 | WARNING | Return type with no return

The class is following:

<?php declare(strict_types=1); # -*- coding: utf-8 -*-

namespace Just\Some\Test\Auth;

use Brain\Nonces\NonceInterface;

/**
 * Interface SettingsPageAuthInterface
 *
 * @package Just\Some\Test\Auth
 */
interface SettingsPageAuthInterface
{

    /**
     * @param array $request_data
     *
     * @return bool
     */
    public function isAllowed(array $request_data = []): bool;

    /**
     * @return NonceInterface
     */
    public function nonce(): NonceInterface;

    /**
     * @return string
     */
    public function cap(): string;
}

When i remove the declare, then i still get the message, which i thought it was fixed, that for interfaces are declare is required:

 1 | ERROR   | File must start with a strict types declaration

[sirbrillig]

Damn, you're right. It's because of this line.

* @package Just\Some\Test\Auth

There's too many possible comment tokens to whitelist. I'm just going to skip comment blocks entirely, which I should have done before.

[gmazzap]

Current code still fail in detection of interface-only files when the file contains shell-style comments, e.g. a code like this:

# Hi there

interface  {}

is still reported for missing strict types.

Reason is that shell-style comment tokens does not have comment_closer attribute. this can be fixed by adding T_COMMENT to the list of ignored toke types.

I've sent a PR (#37) that fixes it.