ci: configure commitlint

Add commitlint to the project, so that we can auto generate changelogs
from now on.

.github/main.workflow

@@ -5,7 +5,7 @@ workflow "Publish typed_json_dataclass" {
 
 workflow "PR Builder" {
   on = "pull_request"
-  resolves = ["Run flake8", "Run pytest"]
+  resolves = ["Run flake8", "Run pytest", "Run commitlint"]
 }
 
 action "Install" {
@@ -44,3 +44,8 @@ action "Publish" {
   secrets = ["PYPI_USERNAME", "PYPI_PASSWORD"]
   args = ["publish", "--build", "--no-interaction", "-vv", "--username", "$PYPI_USERNAME", "--password", "$PYPI_PASSWORD"]
 }
+
+action "Run commitlint" {
+  uses = "./actions/make"
+  args = "commitlint"
+}

Dockerfile

@@ -0,0 +1,5 @@
+FROM node:8.15.0
+WORKDIR /src
+COPY package.json package-lock.json /src/
+RUN npm ci
+COPY .git /src/.git

Makefile

@@ -0,0 +1,17 @@
+SHELL := /bin/bash
+
+CONTAINER_NAME = versioner
+
+.PHONY: help
+help: ## View help information
+	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'
+
+.PHONY: build
+build: ## Build the container to run our commands within a container
+	docker build -t $(CONTAINER_NAME) -f ./Dockerfile .
+
+.PHONY: commitlint
+commitlint: build ## Verify that commits conform to our standard
+	docker run \
+		$(CONTAINER_NAME) \
+		npm run commitlint

actions/make/Dockerfile

@@ -0,0 +1,10 @@
+FROM docker:18.09.6
+LABEL "com.github.actions.name"="Makefile runner"
+LABEL "com.github.actions.description"="A docker base image that can run make"
+LABEL "com.github.actions.icon"="code"
+LABEL "com.github.actions.color"="gray-dark"
+LABEL "maintainer"="abatilo"
+
+RUN apk add make=4.2.1-r2 bash=5.0.0-r0
+COPY ./entrypoint.sh /
+ENTRYPOINT ["/entrypoint.sh"]

actions/make/entrypoint.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+sh -c "make $*"