Obscuro v0.20.1

Change Log

• A list of the commits and PRs merged in this release is as below;
  • 36f69996 Rpc api: ensure hash field included in batches json (#1684)
  • 1ecd222c Enclave: no panic for bad rlp format (#1679)
  • 801d5600 Use the cached head block (#1678)