update vendor (trickstercache#565)

Signed-off-by: James Ranson <[email protected]>

use go 1.16 in beta release builder

1.1 backport via (trickstercache#533)

* fix health check header append defect

* increment version

port fixes from trickstercache#530

bump version to 1.1.4-rc2

increment version 1.1.4-rc1

1.1.3 fixes (trickstercache#488)

* fix waitgroup scoping issues

* trust time is always idx 0 for influxql responses

* fix concurrency issue in series merge

* ensure backfill tolerance only applies to realtime

* update image tag in docker-compose demo project (was using `1.1.0-beta` instead of `1.1`)

* improve clickhouse time series / cacheable detection

* update go 1.15

* update dependencies

bump version

go mod vendor before make test

Merge branch 'master' into v1.1.x