Unbreak syncfree import (#3228)
* Skip syncfree optimizer test in circleci if the package is not available (<=r1.10)
* Revert test_train_mp_imagenet.py to limit the testing scope (avoid testing multiple amp optimizers in the same script)
* Update .circleci/common.sh to check before running syncfree optimizer
tests
* add test_train_mp_imagenet_amp.py for performance evaluation of different amp optimizers based on imagenet
* Install cmake>=3.13 in circleci build image
* Move failing ops test cases to the skiplist (regression)
