Function to write dictionary data, from subsampleReplicates, to file an hdf5 file. 
    :param dictionary: nested dictionary returned by subsampleReplicates
    :param replicateKey: string designating the replicate written to file
    :param outFileName: string defining the hdf5 filename

def dictToFile(dictionary,replicateKey,outFileName):
    '''
    Function to write dictionary data, from subsampleReplicates, to file an hdf5 file. 
    :param dictionary: nested dictionary returned by subsampleReplicates
    :param replicateKey: string designating the replicate written to file
    :param outFileName: string defining the hdf5 filename
    '''
    replicateToFile=h5py.File(outFileName,"w")
    for i in range(len(dictionary[replicateKey])):
        replicateToFile.create_dataset("{}".format(dictionary[replicateKey].keys()[i])\
                                    ,data=dictionary[replicateKey].values()[i]\
                                    ,compression="gzip")
    replicateToFile.close()