README.md in humidifier-1.0.6 vs README.md in humidifier-1.2.1

@@ -6,11 +6,11 @@
 
 Humidifier allows you to build AWS CloudFormation (CFN) templates programmatically. CFN stacks and resources are represented as Ruby objects with accessors for all their supported properties. Stacks and resources have `to_cf` methods that allow you to quickly inspect what will be uploaded.
 
 For the full docs, go to [https://localytics.github.io/humidifier/](http://localytics.github.io/humidifier/). For local development instructions, see the [Development](https://localytics.github.io/humidifier/#label-Development) section.
 
-Humidifier is tested with Ruby 2.0.0 and higher.
+Humidifier is tested with Ruby `2.1` and higher. The gem version is linked to AWS' CloudFormation resource specification version since `1.2.1`.
 
 ## Getting started
 
 Stacks are represented by the `Humidifier::Stack` class. You can set any of the top-level JSON attributes through the initializer. Resources are represented by an exact mapping from `AWS` resource names to `Humidifier` resources names (e.g. `AWS::EC2::Instance` becomes `Humidifier::EC2::Instance`). Resources have accessors for each JSON attribute. Each attribute can also be set through the `initialize`, `update`, and `update_attribute` methods.
 
@@ -78,10 +78,10 @@
 end
 ```
 
 ## Development
 
-To get started, ensure you have ruby installed, version 2.0 or later. From there, install the `bundler` gem: `gem install bundler` and then `bundle install` in the root of the repository.
+To get started, ensure you have ruby installed, version 2.1 or later. From there, install the `bundler` gem: `gem install bundler` and then `bundle install` in the root of the repository.
 
 ### Testing
 
 The default rake task runs the tests. Coverage is reported on the command line, and to coveralls.io in CI. Styling is governed by rubocop. The docs are generated with yard. To run all three of these, run: