Added new SNP class for processing snp and allele files
Added private parsing method of SNPs file
Added get_loci_list method
Added parse operation when initializing a SNPs object
The number of SNPs is now calculated during parsing operation
Starting implementing get_snp_coverage method
Removed unnecessary creation of file object when initializing a Tags object
First implementation of get_snp_coverage method generating a plot
Corrected header
Implemented first operation of generating a species frequency histogram for variable loci
Implemented first operation of generating a species frequency histogram for variable loci
Added prints for progression check
Revision of the data generation
Added line counter method to SNPs