Update damping in simulation models

[fiorisi]

• Updated the damping value of the simulation models
• Removed the box for feet collision from the non-simulation models

[nunoguedelha]

@traversaro , for some reason, YCM is not building on Travis, I have no idea why. Would you have an idea?

[traversaro]

I had the same problem on Jenkins. I will check this evening!

[nunoguedelha]

Now the build on the merge commit on master is failing: https://travis-ci.org/robotology-playground/icub-model-generator/builds/327474219.
this prevents the automatic commit to be done on the repo icub-models. The failure is due to the command "sudo apt-get update" failing, which is due to the GPG key expired on the MongoDB repo. It is apparently a recurrent issue. It is now tracked in travis-ci/travis-ci#9037.

[nunoguedelha]

We could try this workaround marmarek/qubes-builder@f7fa369 which removes the MongoDB repo. MongoDB is a document database (https://www.mongodb.com/what-is-mongodb).
@traversaro do we need this repo? Would it break something if we remove it? I'll give a try..

[nunoguedelha]

The support team released an express fix. It's now working. the build on the merged commit completed successfully.