Set the default graph on entity creation

[claudiu-cristea]

No description provided.

[pfrenssen]

No test results?

[pfrenssen]

OK so our test pipeline is not yet configured, and neither @claudiu-cristea or me have the necessary permissions to set up a CI pipeline. This is out of scope for this issue and is handled in #4.

I have added a simple test to verify that the graph is set. Here are the results from running the tests locally:

$ ../vendor/bin/phpunit modules/contrib/sparql_entity_storage/
PHPUnit 6.5.14 by Sebastian Bergmann and contributors.

Runtime:       PHP 7.3.10
Configuration: /home/pieter/v/joinup-dev/web/phpunit.xml

....S................                                             21 / 21 (100%)

Time: 33.29 seconds, Memory: 10.00MB

There was 1 skipped test:

1) Drupal\Tests\sparql_entity_storage\Kernel\EncodingTest::testEncoding
Library minimaxir/big-list-of-naughty-strings is required.

/home/pieter/v/joinup-dev/web/modules/contrib/sparql_entity_storage/tests/src/Kernel/EncodingTest.php:25

OK, but incomplete, skipped, or risky tests!
Tests: 21, Assertions: 131, Skipped: 1.