Add configuration options to build-ami/packer config

* `aws_access_key` and `aws_secret_key` now default to pulling from the
  AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables.
* `region` is now also settable and will default to AWS_DEFAULT_REGION if
  set in environment (follows convention used by aws cli tool)
* `source_ami` is now a required argument and defaults to the second
  aregument passed to `build-ami`
* `instance_type` is now a variable, still defaults to 'm1.large' but
  can be overriden with a `-var` switch to packer
Add new arg. for build-ami to Readme

Also some minor spelling fixes, cleaning up examples to reference node
instead of Rails, etc.
Remove hard-coded region from deploy script

The aws cli will use the AWS_DEFAULT_REGION environment variable or a
config file in ~/.aws/config if they're present
Set environment variables before running build script.
Merge pull request #3 from mattmmatt/master

Set environment variables before running build script.
Merge pull request #1 from prognostikos/generalize-config

Generalize config
Create LICENSE

Fixes #4
use modern instance for the modern os
add ruby framework
Correct ruby md5

https://www.ruby-lang.org/en/downloads/
bugfix: init with pid dir
install bundler on base
create nginx socket dir
add var/lib to target's home dir
without purpose
Allow deploy to modify rsyslog forwarding.

This way apps can configure their papertrail settings.
Revert "Allow deploy to modify rsyslog forwarding."

This reverts commit 3457722cc0f9d4306c06451ef1ce0c79920fe3d9.
provide mechanism for log configuration
Bugfix: tell apparmor to allow rsyslogd to use net
refactor: use APP_DIR