Add visitors field to events for PATCH support

tests/blog_mysql.sql

   `id` int(11) NOT NULL AUTO_INCREMENT,
   `name` varchar(255) NOT NULL,
   `datetime` datetime(3) NOT NULL,
+  `visitors` int(11) NOT NULL,
   PRIMARY KEY (`id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
 
-INSERT INTO `events` (`id`, `name`, `datetime`) VALUES
-(1,	'Launch', '2016-01-01 13:01:01.111');
+INSERT INTO `events` (`id`, `name`, `datetime`, `visitors`) VALUES
+(1,	'Launch', '2016-01-01 13:01:01.111', 0);
 
 DROP VIEW IF EXISTS `tag_usage`;
 CREATE VIEW `tag_usage` AS select `name`, count(`name`) AS `count` from `tags`, `post_tags` where `tags`.`id` = `post_tags`.`tag_id` group by `name` order by `count` desc, `name`;

tests/blog_postgresql.sql

 CREATE TABLE events (
     id serial NOT NULL,
     name character varying(255) NOT NULL,
-    datetime timestamp NOT NULL
+    datetime timestamp NOT NULL,
+    visitors integer NOT NULL
 );
 
 --
 -- Data for Name: events; Type: TABLE DATA; Schema: public; Owner: postgres
 --
 
-INSERT INTO "events" ("name", "datetime") VALUES
-('Launch',	'2016-01-01 13:01:01.111');
+INSERT INTO "events" ("name", "datetime", "visitors") VALUES
+('Launch',	'2016-01-01 13:01:01.111',	0);
 
 --
 -- Data for Name: events; Type: TABLE DATA; Schema: public; Owner: postgres

tests/blog_sqlite.sql

 CREATE TABLE `events` (
   `id` integer NOT NULL PRIMARY KEY AUTOINCREMENT,
   `name` text(255) NOT NULL,
-  `datetime` datetime NOT NULL
+  `datetime` datetime NOT NULL,
+  `visitors` integer NOT NULL
 );
 
-INSERT INTO `events` (`id`, `name`, `datetime`) VALUES (1,	'Launch',	'2016-01-01 13:01:01.111');
+INSERT INTO `events` (`id`, `name`, `datetime`, `visitors`) VALUES (1,	'Launch',	'2016-01-01 13:01:01.111',	0);
 
 DROP VIEW IF EXISTS `tag_usage`;
 CREATE VIEW `tag_usage` AS select `name`, count(`name`) AS `count` from `tags`, `post_tags` where `tags`.`id` = `post_tags`.`tag_id` group by `name` order by `count` desc, `name`;

tests/blog_sqlserver.sql

 	[id] [int] IDENTITY,
 	[name] [nvarchar](max) NOT NULL,
 	[datetime] [datetime2](3) NOT NULL,
+	[visitors] [int] NOT NULL,
  CONSTRAINT [PK_events] PRIMARY KEY CLUSTERED
 (
 	[id] ASC
 GO
 SET IDENTITY_INSERT [events] ON
 GO
-INSERT [events] ([id], [name], [datetime]) VALUES (1, N'Launch', N'2016-01-01 13:01:01.111')
+INSERT [events] ([id], [name], [datetime], [visitors]) VALUES (1, N'Launch', N'2016-01-01 13:01:01.111', 0)
 GO
 SET IDENTITY_INSERT [events] OFF
 GO