README.md in sidekiq-logstash-3.0.0 vs README.md in sidekiq-logstash-3.1.0

@@ -31,9 +31,10 @@
 ## Installation
 
 Add one of the following lines to your application's Gemfile:
 
 ```ruby
+gem 'sidekiq-logstash', '~> 3.0' # Sidekiq 7
 gem 'sidekiq-logstash', '~> 2.0' # Sidekiq 6
 gem 'sidekiq-logstash', '< 2' # Sidekiq 5 or older
 ```
 
 And then execute: