filter_var has different behavior in PHP 7.x

[peter279k]

Issue summary

The filter_var has the different behavior in the php-7.x versions.

System informations

• OS: Linux/Ubuntu 18.04.2 LTS
• PHP version: php-7.1.30

Standalone code, or other way to reproduce the problem

Please consider following code snippets firstly:

It's for php-7.x:

filter_var('not-int',  FILTER_VALIDATE_INT, ['options' => ['min_range' => 1, 'default' => 20]]); // 20

It's for php-5.x:

filter_var('not-int',  FILTER_VALIDATE_INT, ['options' => ['min_range' => 1, 'default' => 20]]); // false

It effects the line 229 in src/Millipede.php class.

Expected result

The tests will be done and has the green message in php-7.x.

Actual result

The tests will have the failed assertion due to different filter_var behavior in different PHP versions.

PHPUnit 4.8.36 by Sebastian Bergmann and contributors.

Runtime:	PHP 7.1.30-1+ubuntu18.04.1+deb.sury.org+1 with Xdebug 2.7.1
Configuration:	/data/millipede-php/phpunit.xml

.......F......F................................

Time: 389 ms, Memory: 6.00MB

There were 2 failures:

1) MillipedeTest\MillipedeTest::testSetSizeThrowsException
Failed asserting that exception of type "\InvalidArgumentException" is thrown.

2) MillipedeTest\MillipedeTest::testSetCurveThrowsException
Failed asserting that exception of type "\InvalidArgumentException" is thrown.

FAILURES!
Tests: 47, Assertions: 58, Failures: 2.

Once accepting this, I can solve this issue.