Add `GO111MODULE=off` for go get manifest-tool (#2691)

to fix issue #2689
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

Makefile.release

@@ -63,14 +63,14 @@ docker: docker-build
 
 .PHONY: pre
 pre:
-	go get github.com/estesp/manifest-tool
+	GO111MODULE=off go get github.com/estesp/manifest-tool
 
 .PHONY: build
 build:
 	@echo Cleaning old builds
 	@rm -rf build && mkdir build
 	@echo Building: darwin/amd64 - $(VERSION)
-	mkdir -p build/darwin/amd64 && $(MAKE) coredns BINARY=build/darwin/amd64/$(NAME) SYSTEM="GOOS=darwin GOARCH=amd64" CHECKS="godeps" BUILDOPTS=""
+	mkdir -p build/darwin/amd64 && $(MAKE) coredns BINARY=build/darwin/amd64/$(NAME) SYSTEM="GOOS=darwin GOARCH=amd64" CHECKS="" BUILDOPTS=""
 	@echo Building: windows/amd64 - $(VERSION)
 	mkdir -p build/windows/amd64 && $(MAKE) coredns BINARY=build/windows/amd64/$(NAME).exe SYSTEM="GOOS=windows GOARCH=amd64" CHECKS="" BUILDOPTS=""
 	@echo Building: linux/$(LINUX_ARCH) - $(VERSION) ;\

go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible // indirect
 	github.com/dnstap/golang-dnstap v0.0.0-20170829151710-2cf77a2b5e11
+	github.com/estesp/manifest-tool v0.9.0 // indirect
 	github.com/evanphx/json-patch v4.1.0+incompatible // indirect
 	github.com/farsightsec/golang-framestream v0.0.0-20181102145529-8a0cb8ba8710
 	github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568 // indirect
@@ -54,7 +55,6 @@ require (
 	github.com/prometheus/client_golang v0.9.2
 	github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910
 	github.com/prometheus/common v0.0.0-20181126121408-4724e9255275
-	github.com/sirupsen/logrus v1.4.0 // indirect
 	github.com/smartystreets/goconvey v0.0.0-20190306220146-200a235640ff // indirect
 	github.com/soheilhy/cmux v0.1.4 // indirect
 	github.com/spf13/pflag v1.0.3 // indirect