Merge pull request #182 from czj/patch-2

Author: justincase

lib/mollie/client.rb

@@ -50,8 +50,8 @@ def initialize(api_key = nil)
       @api_key         = api_key
       @version_strings = []
 
-      add_version_string 'Mollie/' << VERSION
-      add_version_string 'Ruby/' << RUBY_VERSION
+      add_version_string "Mollie/#{VERSION}"
+      add_version_string "Ruby/#{RUBY_VERSION}"
       add_version_string OpenSSL::OPENSSL_VERSION.split(' ').slice(0, 2).join '/'
     end