Hey. I tried your tutorial but I got a lot of PHP errors and the tests don't run. I can't send you a link to the output since it's my first comment. The first error is:
"1) MyPluginTest::test_my_plugin_add_greeting Error: Call to undefined function my_plugin_add_greeting()"
All the rest are the same as the plugin file is not loading. Also there is an error about Brain Monkey: Error: Call to undefined method Mockery\Expectation::withConsecutive().
Is there something I'm missing? Hope you can help.