Allow semver generator to run without configuration file present.

Makefile

@@ -1,4 +1,4 @@
-LOCAL_VERSION?=$(shell semver-gen generate -l -c config-release.yaml | sed -e 's|SEMVER ||g')
+LOCAL_VERSION?=""
 CI_RUN?=false
 ADDITIONAL_BUILD_FLAGS=""
 
@@ -6,16 +6,31 @@ ifeq ($(CI_RUN), true)
 	ADDITIONAL_BUILD_FLAGS="-test.short"
 endif
 
-all: build
+ifneq ($(shell which semver-gen), "")
+	LOCAL_VERSION="0.0.0-dev"
+else
+	LOCAL_VERSION=$(shell semver-gen generate -l -c config-release.yaml | sed -e 's|SEMVER ||g')
+endif
 
-build:
+.PHONY: help
+help:  ## display this help
+	@awk 'BEGIN {FS = ":.*##"; printf "\nUsage:\n  make \033[36m<target>\033[0m\n\nTargets:\n"} /^[a-zA-Z0-9_-]+:.*?##/ { printf "  \033[36m%-20s\033[0m %s\n", $$1, $$2 }' $(MAKEFILE_LIST)
+
+.PHONY: all
+all: build ## Build all targets
+
+.PHONY: build
+build: ## Build binary
 	go build -o semver-gen -ldflags="-s -w -X main.PKG_VERSION=${LOCAL_VERSION}" *.go
 
-run: build
+# .PHONY: run
-	@./semver-gen
+# run: build ## Build binary and execute it
+# 	@./semver-gen
 
-test:
+.PHONY: test
+test: ## Run whole test suite
 	@go test ./... $(ADDITIONAL_BUILD_FLAGS) -v -race -cover -coverprofile=coverage.out
 
-update:
+.PHONY: update
+update: ## Update all dependencies and sub-packages
 	@go get -u ./...

cmd/main.go

@@ -327,8 +327,7 @@ func main() {
 	if repo.Generate || params.varGenerateInTest {
 		err := repo.ReadConfig(repo.LocalConfigFile)
 		if err != nil {
-			fmt.Println("Unable to find config file", repo.LocalConfigFile)
+			fmt.Println("Unable to find config file semver.yaml. Using defaults and flags.", repo.LocalConfigFile)
-			os.Exit(1)
 		}
 		err = repo.Prepare()
 		if err != nil {