Log Message:
Update to 6.04

Upstream changes:
6.04      2019-04-02 13:09:45Z
  - Remove circular dependency on LWP::RobotUA introduced in 6.02 (GH#29)
    (Olaf Alders)

6.03      2019-04-01 20:56:38Z
  - Remove circular dependency with LWP::UserAgent introduced in 6.02 (GH#27)
    (Olaf Alders)

6.02      2019-04-01 16:03:37Z
  - Added a .mailmap to properly keep up with contributors to the dist.
  - Revised the changelog to follow current format styles
  - Change port number in test (GH#5) (Perlover)