Merge branch 'patch-9' into 'master'

BUILT: use UTC timezone regardless of local TZ

See merge request !1000

Makefile

@@ -3,7 +3,7 @@ PACKAGE_NAME ?= $(NAME)
 export VERSION := $(shell ./ci/version)
 REVISION := $(shell git rev-parse --short=8 HEAD || echo unknown)
 BRANCH := $(shell git show-ref | grep "$(REVISION)" | grep -v HEAD | awk '{print $$2}' | sed 's|refs/remotes/origin/||' | sed 's|refs/heads/||' | sort | head -n 1)
-BUILT := $(shell date +%Y-%m-%dT%H:%M:%S%:z)
+BUILT := $(shell date -u +%Y-%m-%dT%H:%M:%S%z)
 export TESTFLAGS ?= -cover
 
 LATEST_STABLE_TAG := $(shell git -c versionsort.prereleaseSuffix="-rc" -c versionsort.prereleaseSuffix="-RC" tag -l "v*.*.*" --sort=-v:refname | awk '!/rc/' | head -n 1)