Created Data Center and first Chart.

I opted to use chartkick gem: http://ankane.github.io/chartkick/
I’m very impressed by its capabilities :D
Some improvements + more seeds.
Some more example charts.
Changed view slightly.
Merge branch 'dev' into feature/basic_data_center
Adapted data_center to changes of the fix branch.
Merge branch 'feature/basic_data_center' into dev