* Organize imports Use rustfmt to organize imports. Resolve #162 * remove unused imports * Fix clippy complaints * add clippy github action * remove comment for @arnaucube
Add initial MerkleTree implementation, which is a wrapper on top of Plonky2's MerkleTree, with the idea that the future iteration will replace it by the MerkleTree specified at https://0xparc.github.io/pod2/merkletree.html .
