v0.9.3

Used updated version of extended_matrix where bug in rotation_matrix_to_align_with_vector has been fixed

v0.9.2

Updated calculation of principal moments of inertia

v0.9.1

Updated separating of stiffness matrix

v0.9.0

Added simple integration test

v0.4.12

Merge pull request #1 from RomanShushakov/update_extended_matrix

Update version of extended matrix