READMEs: Note on compatibility only with Ruby > 1.9

Author: karmi

README.md

@@ -15,6 +15,8 @@ etc. are planned and/or being worked on._
 
 ## Installation
 
+The libraries are compatible with Ruby 1.9.3 and higher.
+
 Install the `elasticsearch-model` and/or `elasticsearch-rails` package from
 [Rubygems](https://rubygems.org/gems/elasticsearch):
 

elasticsearch-model/README.md

@@ -7,6 +7,7 @@ It aims to simplify integration of Ruby classes ("models"), commonly found
 e.g. in [Ruby on Rails](http://rubyonrails.org) applications, with the
 [Elasticsearch](http://www.elasticsearch.org) search and analytics engine.
 
+The library is compatible with Ruby 1.9.3 and higher.
 
 ## Installation
 

elasticsearch-rails/README.md

@@ -4,6 +4,8 @@ The `elasticsearch-rails` library is a companion for the
 the [`elasticsearch-model`](https://github.com/elasticsearch/elasticsearch-rails/tree/master/elasticsearch-model)
 library, providing features suitable for Ruby on Rails applications.
 
+The library is compatible with Ruby 1.9.3 and higher.
+
 ## Installation
 
 Install the package from [Rubygems](https://rubygems.org):