In order to improve the consistency with other API endpoints, we move
the enable/disable operations to a separate endpoint
/bridges/{id}/enable/[true,false].
In order for the /bridges APIs to be consistent with other APIs, we move
out metrics from GET /bridges/{id} to its own endpoint,
/bridges/{id}/metrics. We also rename /bridges/reset_metrics to
/bridges/metrics/reset.
Stefan Strigler