Fix inertia torque calculation.
Fix inertia torque calculation.

Verify that the angular velocity/acceleration terms are instances of
Vector. This commit will be obsolete with this PR:
https://github.com/sympy/sympy/pull/2199.

jcrist/pydy,jcrist/pydy,skidzo/pydy,oliverlee/pydy,Shekharrajak/pydy,skidzo/pydy,Shekharrajak/pydy,jcrist/pydy,Shekharrajak/pydy,skidzo/pydy,jcrist/pydy,oliverlee/pydy,skidzo/pydy,jcrist/pydy,jcrist/pydy,Shekharrajak/pydy,oliverlee/pydy,jcrist/pydy