Build failing on master branch

[TravisCarden]

Builds are failing on all new pull requests (e.g., #120, #121) due to notices emitted by unit tests on the master branch on CI, presumably due to updates in the Symfony Yaml parser. Example:

$ ./vendor/bin/phpunit
PHPUnit 5.7.9 by Sebastian Bergmann and contributors.

...............................................................  63 / 252 ( 25%)
............................................................... 126 / 252 ( 50%)
............................................................... 189 / 252 ( 75%)
............................................................... 252 / 252 (100%)


Time: 4.75 seconds, Memory: 29.50MB

OK (252 tests, 621 assertions)

Remaining deprecation notices (4)

Duplicate key "type" detected on line 21 whilst parsing YAML. Silent handling of duplicate mapping keys in YAML is deprecated since version 3.2 and will throw \Symfony\Component\Yaml\Exception\ParseException in 4.0: 1x
    1x in ParserTest::testParser from Tests\Behat\Gherkin

Duplicate key "type" detected on line 20 whilst parsing YAML. Silent handling of duplicate mapping keys in YAML is deprecated since version 3.2 and will throw \Symfony\Component\Yaml\Exception\ParseException in 4.0: 1x
    1x in ParserTest::testParser from Tests\Behat\Gherkin

Duplicate key "type" detected on line 19 whilst parsing YAML. Silent handling of duplicate mapping keys in YAML is deprecated since version 3.2 and will throw \Symfony\Component\Yaml\Exception\ParseException in 4.0: 1x
    1x in ParserTest::testParser from Tests\Behat\Gherkin

Duplicate key "type" detected on line 18 whilst parsing YAML. Silent handling of duplicate mapping keys in YAML is deprecated since version 3.2 and will throw \Symfony\Component\Yaml\Exception\ParseException in 4.0: 1x
    1x in ParserTest::testParser from Tests\Behat\Gherkin

[everzet]

Should be fixed now