travis: use Makefile (#181)

Add a bunch of useful makefile targets

Signed-off-by: Dave Cheney <dave@cheney.net>

.travis.yml

@@ -12,4 +12,4 @@ go:
   - tip
 
 script:
-  - go test -v ./...
+  - make check

Makefile

@@ -0,0 +1,52 @@
+PKGS := github.com/pkg/errors
+SRCDIRS := $(shell go list -f '{{.Dir}}' $(PKGS))
+GO := go
+
+check: test vet gofmt unused misspell unconvert gosimple ineffassign
+
+test: 
+	$(GO) test $(PKGS)
+
+vet: | test
+	$(GO) vet $(PKGS)
+
+staticcheck:
+	$(GO) get honnef.co/go/tools/cmd/staticcheck
+	staticcheck $(PKGS)
+
+unused:
+	$(GO) get honnef.co/go/tools/cmd/unused
+	unused -exported $(PKGS)
+
+misspell:
+	$(GO) get github.com/client9/misspell/cmd/misspell
+	misspell \
+		-locale GB \
+		-error \
+		*.md *.go
+
+unconvert:
+	$(GO) get github.com/mdempsky/unconvert
+	unconvert -v $(PKGS)
+
+gosimple:
+	$(GO) get honnef.co/go/tools/cmd/gosimple
+	gosimple $(PKGS)
+
+ineffassign:
+	$(GO) get github.com/gordonklaus/ineffassign
+	find $(SRCDIRS) -name '*.go' | xargs ineffassign
+
+pedantic: check unparam errcheck staticcheck
+
+unparam:
+	$(GO) get mvdan.cc/unparam
+	unparam ./...
+
+errcheck:
+	$(GO) get github.com/kisielk/errcheck
+	errcheck $(PKGS)
+
+gofmt:  
+	@echo Checking code is gofmted
+	@test -z "$(shell gofmt -s -l -d -e $(SRCDIRS) | tee /dev/stderr)"