Run tests in travis, extend readme

Author: pinkeen

.travis.yml

@@ -1,22 +1,33 @@
 os: linux
-language: generic
+language: node_js
+
+node_js:
+  - 10
 
 services:
   - docker
 
 before_install:
   # Cloudfront edge lambdas support nodejs up to 10.x
   - docker pull mageops/aws-lambda-build:nodejs10.x
+  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version version-number
+  - export PATH="$HOME/.yarn/bin:$PATH"
 
 env:
   - LAMBDA_RUNTIME=nodejs-yarn
 
-script: >
-  docker run \
-    --rm \
-    --tty \
-    --volume "$(pwd):/var/app" \
-    mageops/aws-lambda-build:nodejs10.x $LAMBDA_RUNTIME edge-lambda-deploy-package
+jobs:
+  include:
+    - stage: test
+      script: yarn && yarn test && rm -rf node_modules
+
+    - stage: build
+      script: >
+        docker run \
+          --rm \
+          --tty \
+          --volume "$(pwd):/var/app" \
+          mageops/aws-lambda-build:nodejs10.x $LAMBDA_RUNTIME edge-lambda-deploy-package
 
 deploy:
   - provider: releases

README.md

@@ -7,9 +7,17 @@
 -   Using AWS CloudFront as a CDN server.
 -   Docker and [email protected] for development.
 
+
 ## Setting up
 
-### Generating deploy package
+### Use prebuilt deploy packages
+
+If you don't need to modify the code you can use the prebuilt deploy packages
+provided as _assets_ with each [GitHub release](https://github.com/mageops/aws-lambda-cloudfront-edge/releases).
+
+They are built automatically using [Travis CI](https://travis-ci.com/mageops/aws-lambda-cloudfront-edge).
+
+### Build lambda deploy package (optional)
 
 Because our lambda requires native modules in npm packages e.g. for image optimization, compression etc. we need to rebuild entire `node_modules` on the same operating system that AWS Lambda is running on. Then the complete codebase is zipped into `edge-lambda-deploy-package.zip` archive which can be attached in Lambda Management Console.
 
@@ -80,3 +88,5 @@ You will be redirected to function configuration, there you need to setup the fo
 10. Confirm by clicking the `Add` button.
 11. Hit `Save` button at the top-right.
 12. Wait for CloudFront to apply the changes(usually a minute or two).
+
+