v1.3

Add three tasks:

1. Shape pushing to reach
2. Shape pushing to fit a slot
3. Insertion

Supported pushing primitive actions in discrete & continuous modes.
Clean up compatibility bugs.
New example scripts.

Stable tag for curriculum & task decomposition

Fixed compatibility issues with curriculum & task decomposition.
Add new example scripts.

Bug fixing, multi-step tasks updates, etc.

1. Fixed a series of bugs caused by the entanglement between the single- & multi-step task implementations.
2. Adjusted the position control parameters of the gripper so the fingers won't be torn apart during collision.
3. Adjusted some physical properties of the objects & robot arm (friction, etc.).
4. Done some updates & bug-fixings to the task decomposition codes of the multi-step tasks.

First stable version (taros paper version)

This is the version for the publication appeared on Taros 2021 and arxiv