Update changelog

Merge pull request influxdata#6813 from influxdata/js-influxql-golint

Fix golint errors for the influxql package

Merge pull request influxdata#6792 from benbjohnson/show-tag-values

Optimize SHOW TAG VALUES

Update 0.13.0 release date

Merge pull request influxdata#6584 from influxdata/js-6581-show-tag-v…

…alues-where-clause

Fix SHOW TAG VALUES condition to not filter "name" erroneously

Merge pull request influxdata#6562 from influxdata/js-support-depreca…

…ted-config-sections

Support the deprecated [collectd] and [opentsdb] sections temporarily

Update release date for 0.12.2