Added support for motion strategies

Merge branch 'main' into contact_keyframes_breakdown

Merge pull request #382 from erez-tom/ubuntu

Merge branch 'ubuntu' of https://github.com/erez-tom/mujoco_mpc into ubuntu

Use 22.04 w/ clang13 + MacOS15 for GH actions

Use 22.04 w/ clang13 for GH actions

Added save/load and sample motion strategies

Added support for motion strategies

Merge pull request #352 from google-deepmind/deepmind

Add an option to the CEM planner to keep exploring after the variance has converged to a small amount.

Fix the locking on the policy object in cross entropy planner.

Correctly compute plan variance in cross-entropy planner.

Make planning model differentiable.

Add timing information to iLQG planner terminal printing.

Add a parameter to control the arm posture during foot/hand stand in quadruped flat task.