Add Makefile help

Makefile

@@ -1,11 +1,15 @@
-.PHONY: install deps wheel container dist clean test tests update
+.PHONY: help install deps wheel container dist clean distclean test tests \
+				update publish
 SHELL=/bin/bash
 S3_BUCKET=carbon-deploy
-LIBAIO_SO=libaio.so.1.0.1
 ORACLE_ZIP=instantclient-basiclite-linux.x64-18.3.0.0.0dbru.zip
 ECR_REGISTRY=672626379771.dkr.ecr.us-east-1.amazonaws.com
 
-install:
+help: ## Print this message
+	@awk 'BEGIN { FS = ":.*##"; print "Usage:  make <target>\n\nTargets:" } \
+		/^[-_[:alpha:]]+:.?*##/ { printf "  %-15s%s\n", $$1, $$2 }' $(MAKEFILE_LIST)
+
+install: ## Install python dependencies (runs `pipenv install`)
 	pipenv install
 
 vendor/$(ORACLE_ZIP):
@@ -21,31 +25,31 @@ container:
 		-t $(ECR_REGISTRY)/carbon:`git describe --always` \
 		-t carbon:latest .
 
-dist: deps wheel container
+dist: deps wheel container ## Build docker image
 	@tput setaf 2
 	@tput bold
 	@echo "Finished building docker image. Try running:"
 	@echo "  $$ docker run --rm carbon:latest"
 	@tput sgr0
 
-clean:
+clean: ## Remove build artifacts
 	find . -name "*.pyc" -print0 | xargs -0 rm -f
 	find . -name '__pycache__' -print0 | xargs -0 rm -rf
 	rm -rf .coverage .tox *.egg-info .eggs build/ dist/
 
-distclean: clean
+distclean: clean ## Remove build artifacts and vendor libs
 	rm -rf vendor/
 
-test:
+test: ## Run tests
 	tox
 
 tests: test
 
-update:
+update: ## Update all python dependencies
 	pipenv clean
 	pipenv update --dev
 
-publish:
+publish: ## Push and tag the latest image (use `make dist && make publish`)
 	$$(aws ecr get-login --no-include-email --region us-east-1)
 	docker push $(ECR_REGISTRY)/carbon:latest
 	docker push $(ECR_REGISTRY)/carbon:`git describe --always`