v0.2.4
[moe] fix MoE bugs (#1628)
[gemini] add GeminiMemoryManger (#832)
[Gemini] update API of the chunkmemstatscollector. (#2129)
[zero1&2] only append parameters with gradients (#2681)
[NFC] polish colossalai/zero/sharded_param/__init__.py code style (#1717)
[ddp] add is_ddp_ignored (#2434)
[Gemini] add GeminiAdamOptimizer (#1960)