Converted Tests to PHP Unit

I've gone ahead and converted all the tests to PHP Unit. There's a little more cleanup to be done but here's a start. This should hopefully resolve Issue #8. 

In the long run I'd say these should be restructured a little but this is a start.

I am getting 14 failures whereas I was only getting 9 before I converted to PHP Unit. I will research a little but they all look legit.

Also, what would you think of perhaps merging all the Issue{number}Test files into a IssueTest and have the indivual issues tests as methods in there?

The tests can be ran from the **root** of the project after you've composer installed via:

```bash
$ ./vendor/bin/phpunit
```

To run just the creator or parser tests one could respectively do:

```bash
$ ./vendor/bin/phpunit tests/cases/creator
$ ./vendor/bin/phpunit tests/cases/parser
```