Added test datasets

ref_genes.fasta contains a Plasmodium vivax dhps sequence
the fastq reads in test_data contain reads simulated with the standard error
profile in ART, using 30x coverage for 5 random sequences and the referenec gene

```sh
bin/art_illumina -i random.fasta -p -l 50 -f 30 -m 100 -s 10 -o gfr_test_R
```