DB: Add models and migration for badges

models/badge.js

@@ -0,0 +1,24 @@
+'use strict';
+const {
+  Model
+} = require('sequelize');
+module.exports = (sequelize, DataTypes) => {
+  class Badge extends Model {
+    static associate(models) {
+      // A badge can belong to many cards
+      Badge.belongsToMany(models.Character, { through: 'BadgeCharacter' });
+
+      // A badge can belong to many users
+      Badge.belongsToMany(models.User, { through: 'BadgeUser' });
+    }
+  }
+  Badge.init({
+    name: DataTypes.STRING,
+    description: DataTypes.STRING,
+    image: DataTypes.STRING
+  }, {
+    sequelize,
+    modelName: 'Badge',
+  });
+  return Badge;
+};