Issue/effort limits

The effort limits in the URDFs seem to be too small to properly set up controllers in simulation.
Given the large inertias currently used in the URDFs the small effort limits are too small to be able to move the arm and receive a successful result from the follow_joint_trajectory action.
As I don't know the proper inertias, increasing the effort limits was the easiest fix for now.

At least it can be used in simulation with this PR.
We still can lateron adjust inertias, effort limits and other dynamic parameters in a next iteration.