Update the changelog for 2.7.0 (on-going version). [skip ci]
Update the changelog for 2.7.0 (on-going version). [skip ci]

LedgerHQ/lib-ledger-core,LedgerHQ/lib-ledger-core,LedgerHQ/lib-ledger-core,LedgerHQ/lib-ledger-core,LedgerHQ/lib-ledger-core,LedgerHQ/lib-ledger-core,LedgerHQ/lib-ledger-core