Add lint and continuous integration

.travis.yml

@@ -0,0 +1,8 @@
+language: go
+go:
+  - "1.9"
+install:
+  - make install-ci
+script:
+  - make ci
+

Makefile

@@ -1,6 +1,43 @@
+
+GO_FILES := $(shell git ls-files | grep "\.go$$")
+
+PACKAGES := $(shell find $(GO_FILES) | xargs -n1 dirname | sed 's:^:./:'| uniq)
+
+.PHONY: test
 test:
 	go test ./...
 
+.PHONY: gofmt
+gofmt:
+	gofmt -e -s -l $(GO_FILES)
+
+.PHONY: govet
+govet:
+	go vet ./...
+
+.PHONY: golint
+golint:
+	golint $(PACKAGES)
+
+.PHONY: errcheck
+errcheck:
+	errcheck -ignoretests $(PACKAGES)
+
+.PHONY: lint
+lint: gofmt govet golint errcheck
+
+.PHONY: install
+install:
+	dep ensure
+
+.PHONY: install-ci
+install-ci:
+	go get -u github.com/golang/dep/cmd/dep github.com/golang/lint/golint github.com/kisielk/errcheck
+	dep ensure
+
+.PHONY: ci
+ci: test lint
+
 run/%: proofs/%
 	go run $(shell find $< -maxdepth 1 -name *.go -not -name *_test.go)