Fail if there is no assert in test

[janmarek]

I wrote my first test with TestCase and I forgot to run the test case ( (new SomethingTestCase())->run(); ). This might be common mistake for former PHPUnit users.

Tester said that there was 1 passed test.

I thing that error or at least warning would be better if there is no assert in test.

[milo]

Related to #32.

If you annotate test file by @testCase you get hint.

[fprochazka]

@milo when you define the testcase, you usually have to include autoloader and run Tester\Environment::setup();, so there could be some shutdown handler, that would check if there are loaded non-abstract testcase classes and at least one was ran. There could be some private static counter on the testcase class that the handler would check and report if the run call is missing.

[milo]

@fprochazka Jop. We were discuss with @dg something similar (as here). I'll send PR during the week.