Explain how to set the region used by the script
Explain how to set the region used by the script

Without setting the environment variable, my existing template which was converted to ruby failed as follows:
```
Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:353:in `fetch': key not found: :"us-east-1" (KeyError)
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:353:in `get'
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:354:in `find_in_map'
	from ./ssl_autoscale-STAN-1574.rb:385:in `block in <main>'
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:246:in `instance_eval'
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:246:in `initialize'
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:279:in `initialize'
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:270:in `new'
	from /Library/Ruby/Gems/2.0.0/gems/cloudformation-ruby-dsl-0.4.12/lib/cloudformation-ruby-dsl/cfntemplate.rb:270:in `template'
	from ./ssl_autoscale-STAN-1574.rb:8:in `<main>'
```
FluidInc/cloudformation-ruby-dsl,johnlabarge/cloudformation-ruby-dsl