fix rubocop warnings

lib/instapaper/client.rb

@@ -16,10 +16,10 @@ module Instapaper
     # @param options [Hash]
     # @return [Instapaper::Client]
     def initialize(options = {})
-     options.each do |key, value|
-       instance_variable_set("@#{key}", value)
-     end
-     yield(self) if block_given?
+      options.each do |key, value|
+        instance_variable_set("@#{key}", value)
+      end
+      yield(self) if block_given?
     end
 
     # @return [String]

lib/instapaper/error.rb

@@ -44,7 +44,7 @@ module Instapaper
       BOOKMARK_ERRORS,
       FOLDER_ERRORS,
       HIGHLIGHT_ERRORS,
-    ].collect { |e| e.keys }.flatten
+    ].collect(&:keys).flatten
 
     # Create a new error from an HTTP response
     #

lib/instapaper/http/request.rb

@@ -49,9 +49,9 @@ module Instapaper
       end
 
       def error(code)
-        if Instapaper::Error::CODES.index(code.to_i)
-          Instapaper::Error.from_response(code, @path)
-        end
+        return unless Instapaper::Error::CODES.index(code.to_i)
+
+        Instapaper::Error.from_response(code, @path)
       end
 
       def symbolize_keys!(object)