chore(Makefile): add GONOSUMDB and GOPROXY

Makefile

@@ -12,29 +12,48 @@ ls:
 # Download dependencies
 .PHONY: download
 download:
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go mod download
 
 # Update project dependencies
 .PHONY: update
 update:
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go get -u
+
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go mod download
+
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go mod tidy
 
 # Run project tests
 .PHONY: test
 test: download
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go test ./... -v -race
 
 # Look for "suspicious constructs" in source code
 .PHONY: vet
 vet: download
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go vet ./...
 
 # Format code
 .PHONY: fmt
 fmt: download
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go mod tidy
+
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
 		go fmt ./...
 
 # Check for unformatted go code
@@ -45,7 +64,10 @@ check/fmt: download
 # Build project
 .PHONY: build
 build:
-	CGO_ENABLED=0 go build \
+	CGO_ENABLED=0
+	GONOSUMDB=${GONOSUMDB} \
+	GOPROXY=${GOPROXY} \
+		go build \
 			-ldflags "\
 				-X main.version=${shell git describe --tags} \
 				-X main.commit=${shell git rev-parse HEAD} \