Change:

• Update web3p/rlp to 0.3.2, remove Buffer object from rlp library.
• Update elliptic-php to 1.0.6 (CVE-2019-10764)
  In elliptic-php versions priot to 1.0.6, Timing attacks might be possible which can result in practical recovery of the long-term private key generated by the library under certain conditions. Leakage of a bit-length of the scalar during scalar multiplication is possible on an elliptic curve which might allow practical recovery of the long-term private key.