Wrap Errno::ETIMEDOUT in Faraday::Error::TimeoutError

Closes #324

lib/faraday/adapter/em_synchrony.rb

@@ -70,6 +70,8 @@ module Faraday
         else
           raise Error::ConnectionFailed, err
         end
+      rescue Errno::ETIMEDOUT => err
+        raise Error::TimeoutError, err
       rescue RuntimeError => err
         if err.message == "connection closed by server"
           raise Error::ConnectionFailed, err

lib/faraday/adapter/httpclient.rb

@@ -40,7 +40,7 @@ module Faraday
         save_response env, resp.status, resp.body, resp.headers
 
         @app.call env
-      rescue ::HTTPClient::TimeoutError
+      rescue ::HTTPClient::TimeoutError, Errno::ETIMEDOUT
         raise Faraday::Error::TimeoutError, $!
       rescue ::HTTPClient::BadResponseError => err
         if err.message.include?('status 407')

lib/faraday/adapter/net_http.rb

@@ -54,7 +54,7 @@ module Faraday
         end
 
         @app.call env
-      rescue Timeout::Error => err
+      rescue Timeout::Error, Errno::ETIMEDOUT => err
         raise Faraday::Error::TimeoutError, err
       end
 

lib/faraday/adapter/net_http_persistent.rb

@@ -23,6 +23,8 @@ module Faraday
 
       def perform_request(http, env)
         http.request env[:url], create_request(env)
+      rescue Errno::ETIMEDOUT => error
+        raise Faraday::Error::TimeoutError, error
       rescue Net::HTTP::Persistent::Error => error
         if error.message.include? 'Timeout'
           raise Faraday::Error::TimeoutError, error