add vendor

vendor/github.com/Masterminds/semver/Makefile

@@ -0,0 +1,36 @@
+.PHONY: setup
+setup:
+	go get -u gopkg.in/alecthomas/gometalinter.v1
+	gometalinter.v1 --install
+
+.PHONY: test
+test: validate lint
+	@echo "==> Running tests"
+	go test -v
+
+.PHONY: validate
+validate:
+	@echo "==> Running static validations"
+	@gometalinter.v1 \
+	  --disable-all \
+	  --enable deadcode \
+	  --severity deadcode:error \
+	  --enable gofmt \
+	  --enable gosimple \
+	  --enable ineffassign \
+	  --enable misspell \
+	  --enable vet \
+	  --tests \
+	  --vendor \
+	  --deadline 60s \
+	  ./... || exit_code=1
+
+.PHONY: lint
+lint:
+	@echo "==> Running linters"
+	@gometalinter.v1 \
+	  --disable-all \
+	  --enable golint \
+	  --vendor \
+	  --deadline 60s \
+	  ./... || :