Writes out and err (both should be strings) to logfile.

def write_to_logfile(out, err, logfile, samplelog=None, sampleerr=None, analysislog=None, analysiserr=None):
    """
    Writes out and err (both should be strings) to logfile.
    """
    # Run log
    with open(logfile + '_out.txt', 'a+') as outfile:
        outfile.write(out + '\n')
    with open(logfile + '_err.txt', 'a+') as outfile:
        outfile.write(err + '\n')
    # Sample log
    if samplelog:
        with open(samplelog, 'a+') as outfile:
            outfile.write(out + '\n')
        with open(sampleerr, 'a+') as outfile:
            outfile.write(err + '\n')
    # Analysis log
    if analysislog:
        with open(analysislog, 'a+') as outfile:
            outfile.write(out + '\n')
        with open(analysiserr, 'a+') as outfile:
            outfile.write(err + '\n')