The four bases found in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T).
In genetics, GC-content is the percentage of Guanine (G) and Cytosine (C) bases on a DNA molecule that are either guanine or cytosine.
Given a DNA sequence (a string) return the GC-content in percent, rounded up to 2 decimal digits.
For more information about GC-content you can take a look to wikipedia GC-content.
For example: the GC-content of the following DNA sequence is 50%: "AAATTTCCCGGG".
phpunit KataTest.php
When one test passed, remove the line $this->markTestSkipped();
into the next one for enable it.