Fog::AWS::Storage don't retry client errors (#691)

* Fog::AWS::Storage don't retry client errors

Resolves #690

* Fog::AWS::Storage merge connection options

lib/fog/aws/storage.rb

@@ -14,6 +14,14 @@ class Storage < Fog::Service
         'https' => 443
       }
 
+      DEFAULT_CONNECTION_OPTIONS = {
+        retry_limit: 5,
+        retry_interval: 1,
+        retry_errors: [
+          Excon::Error::Timeout, Excon::Error::Socket, Excon::Error::Server
+        ]
+      }
+
       MIN_MULTIPART_CHUNK_SIZE = 5242880
       MAX_SINGLE_PUT_SIZE = 5368709120
 
@@ -546,7 +554,8 @@ def initialize(options={})
           @use_iam_profile = options[:use_iam_profile]
           @instrumentor       = options[:instrumentor]
           @instrumentor_name  = options[:instrumentor_name] || 'fog.aws.storage'
-          @connection_options     = options[:connection_options] || { retry_limit: 5, retry_interval: 1 }
+          @connection_options =
+            DEFAULT_CONNECTION_OPTIONS.merge(options[:connection_options] || {})
           @persistent = options.fetch(:persistent, false)
           @acceleration = options.fetch(:acceleration, false)
           @signature_version = options.fetch(:aws_signature_version, 4)