Adding missing weekday method tests.

[jhoughtelin]

This implements tests for weekday methods that were lacking tests. This includes tests for Event->tuesdays(), Event->wednesdays(), Event->weekdays() and Event->weeklyOn()

This PR just adds a little bit more test coverage specifically for the weekday methods.

Before:

PHPUnit 5.5.4 by Sebastian Bergmann and contributors.

Runtime:       PHP 7.0.9 with Xdebug 2.4.1
Configuration: /Volumes/CODE/projects/crunz_jh/phpunit.xml

............                                                      12 / 12 (100%)

Time: 181 ms, Memory: 12.00MB

OK (12 tests, 46 assertions)

After:

PHPUnit 5.5.4 by Sebastian Bergmann and contributors.

Runtime:       PHP 7.0.9 with Xdebug 2.4.1
Configuration: /Volumes/CODE/projects/crunz_jh/phpunit.xml

............                                                      12 / 12 (100%)

Time: 164 ms, Memory: 12.00MB

OK (12 tests, 50 assertions)

[jhoughtelin]

Auto-formatting fail. =(

[PabloKowalczyk]

Thanks @jhoughtelin.