Url issue

Fix the bug for important sub-metrics
This is really long.
We should use the `csv` module and then we can do the following:

```python
with open(imp_metric_stats_csv_file, 'w') as FH_IMP:
  csvwriter = csv.writer(FH_IMP)
  csvwriter.writerow(header)
  ...
  fn = lamda x: round(x, 2)
  csv_data = [sub_metric] + map(fn, [stats_data['mean'], stats_data['std'], percentile_data[50], 
                                    percentile_data[75], percentile_data[90], percentile_data[95],
                                    percentile_data[99], stats_data['min'], stats_data['max']])
  csvwriter.writerow(csv_data)
```

We can also split the lines so it's easier to read. We should set a standard of 80 or 120 characters per line.