Fix route configuration for issuing a computation

When I updated the route configuration file, I accidentally have
overwritten the route for issuing a metric computation with the
GET method instead of the required POST method.

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

I have added a validation module which serves me to semi-automate my
validation process a bit. I do not know yet whether this module will
be kept for the actual application.

Signed-off-by: Konrad Reiche <konrad.reiche@gmail.com>
Update progress bar elements to Bootstrap 3

Bootstrap 3 uses now the class progress-bar instead of just bar. Hence,
this commit to update the classes.

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