init commit

store/migration/mysql/0.20/00__reaction.sql

@@ -0,0 +1,9 @@
+-- reaction
+CREATE TABLE `reaction` (
+  `id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
+  `created_ts` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  `creator_id` INT NOT NULL,
+  `content_id` VARCHAR(256) NOT NULL,
+  `reaction_type` VARCHAR(256) NOT NULL,
+  UNIQUE(`creator_id`,`content_id`,`reaction_type`)  
+);