Only accepts SQL store

When SQL & MongoDB stores are together then It sequelize fires error that MongoDB dialect not supported.
So check only SQL stores from config to work sequelize & mongoose together.

Author: Nishchit14

lib/transformer.js

@@ -48,12 +48,23 @@ module.exports = {
       return new Sequelize(config.database, config.username, config.password, config)
     }
   },
+  
+  /**
+	 * Pick only SQL stores from app config
+	 * @param {Object} stores
+	 * @return {Object}
+	 */
+	pickStores (stores) {
+		return _.pickBy(stores, (_store, name) => {
+			return (_store.dialect && _.isString(_store.dialect))
+		})
+	},
 
   /**
    * Transform the Trails.js "stores" config into a Sequelize object
    */
   transformStores (app) {
-    const stores = app.config.database.stores
+    const stores = this.pickStores(app.config.database.stores)
     const sequelize = {}
     Object.keys(stores).forEach(key => {
       sequelize[key] = this.createFromConfig(stores[key])