Resolve conflict with Makefile updated by nightly

Author: jerusdp

Makefile

@@ -2,16 +2,17 @@ DOCKER ?= docker
 INPUT_RELEASE_VERSION ?= 0.4.0
 RUST_VERSION ?= 1.55.0
 REPO ?= rustserverless/lambda-rust
+TAG ?= latest
 
 publish: build
-	$(DOCKER) push $(REPO):latest
+	$(DOCKER) push $(REPO):${TAG}
 
 publish-tag: build publish
-	$(DOCKER) tag $(REPO):latest "$(REPO):$(INPUT_RELEASE_VERSION)-rust-$(RUST_VERSION)"
+	$(DOCKER) tag $(REPO):${TAG} "$(REPO):$(INPUT_RELEASE_VERSION)-rust-$(RUST_VERSION)"
 	$(DOCKER) push "$(REPO):$(INPUT_RELEASE_VERSION)-rust-$(RUST_VERSION)"
 
 build:
-	$(DOCKER) build --build-arg RUST_VERSION=$(RUST_VERSION) -t $(REPO):latest .
+	$(DOCKER) build --build-arg RUST_VERSION=$(RUST_VERSION) -t $(REPO):${TAG} .
 
 test:
 	@tests/test.sh
@@ -23,7 +24,7 @@ debug: build
 		-v ${HOME}/.cargo/registry:/cargo/registry \
 		-v ${HOME}/.cargo/git:/cargo/git  \
 		--entrypoint=/bin/bash \
-		$(REPO)
+		$(REPO):$(TAG)
 
 check: 
 	$(DOCKER) run --rm \