Updated works for qiime-tools 1.1.3

barcode_filter.py: added an if condition for checking is quality data
file is supplied by the user.
biom_relative_abundance.py: imported biom_calc, updated the function to
use the newer version of relative_abundance() function form
biom_calc.py.
biom_calc.py: updated relative_abundance() function so that it
calculates the data for all samples of a biom file. Function takes only
one argument now (biom file).
test_biom_calc.py: updated the testing scripts for the newly updated
biom_calc scripts.