Merge branch 'master' into client-go-v4

# Conflicts:
#	cmd/main.go
#	glide.lock
#	pkg/cluster/cluster.go
#	pkg/cluster/exec.go
#	pkg/cluster/k8sres.go
#	pkg/cluster/pod.go
#	pkg/cluster/resources.go
#	pkg/cluster/util.go
#	pkg/cluster/volumes.go
#	pkg/controller/controller.go
#	pkg/controller/pod.go
#	pkg/controller/postgresql.go
#	pkg/controller/util.go
#	pkg/spec/postgresql.go
#	pkg/spec/postgresql_test.go
#	pkg/spec/types.go
#	pkg/util/k8sutil/k8sutil.go
#	pkg/util/util.go
#	pkg/util/util_test.go