Improve and simplify configuration

* Customization improvements

    1) Fill variables in .env instead deploy.env and Makefile
    2) Autodetecting CloudWatch events.
    3) Remove slackbot customization

* Use npm scripts instead of makefile
* Fix image urls in readme
* Changed env variables examples and fixed names in scripts
* Remove old node versions from TravisCI

v0.2.1 - Add catch-all message for AWS services that aren't specifica…

…lly supported

Merge pull request #13 from assertible/wip-pin-node-lambda

Pin node-lambda package to 0.8.11