Refactoring tests

[carusogabriel]

I've refactored some tests, using:

• assertCount instead of count function;
• assertArrayHasKey instead of isset function;
• assertInternalType instead of is_string function;
• assertGreaterThan for mathematical comparisons.

[giorgiosironi]

The master builds seemed to work at https://travis-ci.org/giorgiosironi/phpunit-selenium/branches while this build is failing for unrelated reasons?

[giorgiosironi]

Now master fails too, ok.

[giorgiosironi]

Opened sebastianbergmann/phpunit#2950 to check why the master test suite started to fail.

[carusogabriel]

Ok. I’m out of my home now, but as soon as I return to it, I’ll check the fails!