Move to Docker compose for better reproducability

docker-compose.yml

@@ -0,0 +1,28 @@
+version: '2.4'
+services:
+  lambci:
+    build:
+      context: ./build/docker
+      dockerfile: ../../Dockerfile
+    image: lambci/lambci
+    # Lambda only has these files/links in /dev:
+    # /dev/full
+    # /dev/null
+    # /dev/random
+    # /dev/stderr
+    # /dev/stdin
+    # /dev/stdout
+    # /dev/urandom
+    # /dev/zero
+    volumes:
+      - /var/empty:/dev/fd
+      - /var/empty:/dev/shm
+      - /var/empty:/dev/mqueue
+      # - /var/empty:/dev/pts
+      - /dev/null:/dev/core
+      - /dev/null:/dev/tty
+      # - type: tmpfs
+        # target: /tmp
+        # tmpfs:
+          # size: 500M
+    mem_limit: 3G

package.json

@@ -18,7 +18,7 @@
     "zip": "rm -rf build/lambda.zip node_modules && npm ci --prod && zip -qyr build/lambda.zip . -x@.lambdaignore",
     "package": "npm run zip && sam package --template-file template.yaml --s3-bucket ${S3_BUCKET:-lambci} --s3-prefix ${S3_PREFIX:-package} --output-template-file build/packaged.yaml",
     "deploy": "npm run package && sam deploy --stack-name ${STACK:-lambci} --template-file build/packaged.yaml --capabilities CAPABILITY_IAM",
-    "docker": "npm run zip && cd build && rm -rf docker && unzip lambda.zip -d docker && docker build -t lambci/lambci -f ../Dockerfile docker"
+    "docker": "npm run zip && rm -rf build/docker && unzip build/lambda.zip -d build/docker && docker-compose build"
   },
   "dependencies": {
     "ansi_up": "^3.0.0",