Version 1.6.5 release.

Version 1.6.4 release.

updating relase notes generation

Release v1.6.2

Merge pull request #897 from fabiolb/release/v1.6

Release/v1.6.1

fix bug where metrics could not be disabled

Preparing for 1.5.15 release

Merge pull request #785 from fabiolb/release/1.5.14

updating documentation for pending 1.5.14 release

Update Dockerfile to go1.13.4