Add linting and formatting configurations with makefile

Signed-off-by: Sambhav Kothari <skothari44@bloomberg.net>

Makefile

@@ -0,0 +1,25 @@
+# Go parameters
+GOCMD?=go
+GO_VERSION=$(shell go list -m -f "{{.GoVersion}}")
+PACKAGE_BASE=github.com/buildpacks/libcnb
+
+all: test
+
+install-goimports:
+	@echo "> Installing goimports..."
+	cd tools && $(GOCMD) install golang.org/x/tools/cmd/goimports
+
+format: install-goimports
+	@echo "> Formating code..."
+	@goimports -l -w -local ${PACKAGE_BASE} .
+
+install-golangci-lint:
+	@echo "> Installing golangci-lint..."
+	cd tools && $(GOCMD) install github.com/golangci/golangci-lint/cmd/golangci-lint
+
+lint: install-golangci-lint
+	@echo "> Linting code..."
+	@golangci-lint run -c golangci.yaml
+
+test: format lint
+	$(GOCMD) test -parallel=1 -count=1 -v ./...

golangci.yaml

@@ -0,0 +1,32 @@
+run:
+  timeout: 6m
+
+linters:
+  disable-all: true
+  enable:
+    - bodyclose
+    - deadcode
+    - dogsled
+    - gocritic
+    - goimports
+    - golint
+    - gosec
+    - gosimple
+    - govet
+    - ineffassign
+    - maligned
+    - misspell
+    - nakedret
+    - scopelint
+    - staticcheck
+    - structcheck
+    - stylecheck
+    - typecheck
+    - unconvert
+    - unused
+    - varcheck
+    - whitespace
+
+linters-settings:
+  goimports:
+    local-prefixes: github.com/buildpacks/libcnb

tools/go.mod

@@ -0,0 +1,7 @@
+module github.com/buildpacks/libcnb/tools
+
+go 1.15
+
+require golang.org/x/tools v0.1.4
+
+require github.com/golangci/golangci-lint v1.41.1