1.6.0

• Behavior change! Default to sending the plain text email address rather
  than its MD5 hash. Previously only the MD5 hash of the email address
  would be sent, and sending the plain text email address was not possible.
  If you wish to send only the MD5 hash of the email address, you must now
  call hashAddress() on the Email builder in addition to address().
• When sending a hashed email address, the address is now lower-cased
  before the MD5 is calculated.
• Update Jackson and WireMock dependencies.