Fix failing MassSpring*DRepresentationTests.Init*DTests.

- Update the test case to test the boundary conditions interems of dof ID.
Add UnitTest for DeformableCollisionRepresentation

Note:
1. Serialization is not done yet.
2. DeformableCollisionRepresentation owns a MeshShape and a Mesh,
   they seem redundant.
3. Bug in MeshShape is fixed in another merge request (that
   'computeVolumeIntegrals()' needs to be called within 'setFileName()'.
Merge branch 'fix/mass-spring-unit-test' into 'master'

Fix failing MassSpring*DRepresentationTests.Init*DTests.

+1: Julien Lenoir, Ryan Beasley, haizhouW

Merged-on: https://www.assembla.com/code/OpenSurgSim/git/merge_requests/866623
Revise DeformableCollisionRepresentation and its UnitTest
Revise DeformableCollisionRepresentation and its UnitTest
(Repeated) Fix bug in MeshShape
Update UnitTest for Fem3DRepresentation
Merge remote-tracking branch 'origin/master' into wip/serialization-deformable