highlight head so I instantly know it is running on latest

@semipermeable

my normal workflow after amending / adding is seeing if tddium is running the latest commit or something old (have to stop it and start a new build), this makes this easier since I then no longer have to look through my git log to see what my head is and compare.

before: no idea if it's running latest
![screen shot 2014-08-22 at 2 45 10 pm](https://cloud.githubusercontent.com/assets/11367/4017930/e244ce5a-2a45-11e4-9601-2d7610f4957e.png)

after: head build is highlighted
![screen shot 2014-08-22 at 2 44 43 pm](https://cloud.githubusercontent.com/assets/11367/4017928/e056535c-2a45-11e4-9ffd-d7d1b807c73d.png)




print_table does not support colors and build big columns (tried to patch it, but it's super complicated ...)
so I went with capture -> replace -> print