v2.8.4

• Update node-xml-encryption with the latest upstream update for security patch (#474)
• Fix broken tests after upgrade
• Take default encryption key algorithm as http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p
  • The previous default is no longer to be recommended, for more detail, https://github.com/auth0/node-xml-encryption/blob/291f3f10d5d1d571a3b6da2d411aa323398f5650/lib/xmlenc.js#L54-L56
• Upgrade dev dependencies