Add Torobo and Torobo Hand

[mamoruoka]

This PR adds the Torobo and Torobo Hand model (issue #113).
Please feel free to suggest any suggestions to improve the quality of this PR.

[google-cla]

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[mamoruoka]

Please wait a few days until our company's agreement about CLA is approved.

[mamoruoka]

Our company's agreement about CLA has been approved, so please review this PR.

[kevinzakka]

Hi @mamoruoka, will get to this next week, a bit busy with finals this week.

[mamoruoka]

I found mistakes in the models and have corrected it.
Thank you for your review next week, @kevinzakka .