Stress calculator output

```shell
$ bundle exec ./bin/stressfactor analyze ~/Dropbox/Apps/Velocitas\ Uploader/Runmeter-Run-20141102-0826.gpx

Units are metric, which are in min/km
Grade Adjusted Pace: 5.805211157124562
Raw Pace: 6.6699461299300955
Training stress score: 642.0620191529506
```