Fix rubocop issues

Author: cyberdelia

lib/rubocop/cop/sequel/column_default.rb

@@ -13,6 +13,7 @@ class ColumnDefault < Cop
 
         def on_send(node)
           return unless add_column_default?(node)
+
           add_offense(node, location: :selector, message: MSG)
         end
       end

lib/rubocop/cop/sequel/concurrent_index.rb

@@ -24,6 +24,7 @@ def on_send(node)
         def offensive?(args)
           !args.last.hash_type? || args.last.each_descendant.none? do |n|
             next unless n.sym_type?
+
             n.children.any? { |s| s == :concurrently }
           end
         end

lib/rubocop/cop/sequel/json_column.rb

@@ -21,13 +21,16 @@ class JSONColumn < Cop
 
         def on_send(node)
           return unless json_or_hstore?(node)
+
           add_offense(node, location: :selector, message: MSG)
         end
 
         def on_block(node)
           return unless node.send_node.method_name == :create_table
+
           node.each_node(:send) do |method|
             next unless column_method?(method) || column_type?(method)
+
             add_offense(method, location: :selector, message: MSG)
           end
         end

lib/rubocop/cop/sequel/save_changes.rb

@@ -14,6 +14,7 @@ class SaveChanges < Cop
 
         def on_send(node)
           return unless model_save?(node)
+
           add_offense(node, location: :selector, message: MSG)
         end