p1: /v2/scrape, /v1/fetch, auth, CLI, contract tests

Single Fetcher.Fetch on the Guard that holds DenyPrefixes. skipTlsVerification
is ignored. No 502. keys add writes the secret only to --out. Release binary
has no -test-allow-prefix.

vendor/github.com/itchyny/timefmt-go/Makefile

@@ -0,0 +1,20 @@
+GOBIN ?= $(shell go env GOPATH)/bin
+
+.PHONY: all
+all: test
+
+.PHONY: test
+test:
+	go test -v -race ./...
+
+.PHONY: lint
+lint: $(GOBIN)/staticcheck
+	go vet ./...
+	staticcheck -checks all,-ST1000 ./...
+
+$(GOBIN)/staticcheck:
+	go install honnef.co/go/tools/cmd/staticcheck@latest
+
+.PHONY: clean
+clean:
+	go clean