README.md in faraday_middleware-aws-signers-v4-0.1.1 vs README.md in faraday_middleware-aws-signers-v4-0.1.2

@@ -2,10 +2,11 @@
 
 [Faraday](https://github.com/lostisland/faraday) middleware for AWS Signature Version 4.
 
 [![Gem Version](https://badge.fury.io/rb/faraday_middleware-aws-signers-v4.svg)](http://badge.fury.io/rb/faraday_middleware-aws-signers-v4)
 [![Build Status](https://travis-ci.org/winebarrel/faraday_middleware-aws-signers-v4.svg)](https://travis-ci.org/winebarrel/faraday_middleware-aws-signers-v4)
+[![Coverage Status](https://coveralls.io/repos/winebarrel/faraday_middleware-aws-signers-v4/badge.svg?branch=master&service=github)](https://coveralls.io/github/winebarrel/faraday_middleware-aws-signers-v4?branch=master)
 
 ## Installation
 
 Add this line to your application's Gemfile:
 
@@ -29,9 +30,11 @@
 require 'pp'
 
 conn = Faraday.new(url: 'https://apigateway.us-east-1.amazonaws.com') do |faraday|
   faraday.request :aws_signers_v4,
     credentials: Aws::Credentials.new(ENV['AWS_ACCESS_KEY_ID'], ENV['AWS_SECRET_ACCESS_KEY']),
+    # If you use the credentials file:
+    #credentials: Aws::SharedCredentials.new.credentials,
     service_name: 'apigateway',
     region: 'us-east-1'
 
   faraday.response :json, :content_type => /\bjson$/
   faraday.response :raise_error