release: kill sum target (#2069)

Just create the sha256 inline so we know there are there.
Add a 'version' target in Makefile.release that prints the version so we
can double check that easily in the release script.
Signed-off-by: Miek Gieben <miek@miek.nl>

Makefile.release

@@ -55,7 +55,7 @@ endif
 all:
 	@echo Use the 'release' target to build a release, 'docker' for docker build.
 
-release: pre build tar sum
+release: pre build tar
 
 docker: docker-build
 
@@ -86,12 +86,6 @@ tar:
 	    tar -zcf release/$(NAME)_$(VERSION)_linux_$$arch.tgz -C build/linux/$$arch $(NAME) ;\
 	done
 
-.PHONY: sum
-sum:
-	for asset in `ls -A release/*tgz`; do \
-	    sha256sum $$asset > $$asset.sha256; \
-	done
-
 .PHONY: github-push
 github-push:
 	@echo Releasing: $(VERSION)
@@ -104,6 +98,9 @@ github-push:
 	      --data-binary "@$$asset" \
 	      "https://uploads.github.com/repos/$(GITHUB)/$(NAME)/releases/$(RELEASE)/assets?name=$${asset}&access_token=${GITHUB_ACCESS_TOKEN}" ; \
 	done
+	for asset in `ls -A release/*tgz`; do \
+	    sha256sum $$asset > $$asset.sha256; \
+	done
 	@for asset in `ls -A release/*sha256`; do \
 	    echo $$asset; \
 	    curl -o /dev/null -X POST \
@@ -136,6 +133,10 @@ docker-push:
 	manifest-tool push from-args --platforms $(PLATFORMS) --template $(DOCKER_IMAGE_NAME):coredns-ARCH --target $(DOCKER_IMAGE_NAME):$(VERSION)
 	manifest-tool push from-args --platforms $(PLATFORMS) --template $(DOCKER_IMAGE_NAME):coredns-ARCH --target $(DOCKER_IMAGE_NAME):latest
 
+.PHONY: version
+version:
+	@echo $(VERSION)
+
 .PHONY: clean
 clean:
 	rm -rf release