Pass current repository object via gon

In order to display the current metric scores I have to retrieve the
current repository object via gon. In the next step I will refactor
the metric meter object management inside the metric CoffeeScript.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Set metric scores on accessing the metric overview

Until now the metric results were only visualized after their
computation has finished, but since the results are stored in
the database as well, they can be displayed when loading the
metric dashboard. This commit implements that.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>