feat(promises): add back afterEach and .return(self) on sync

lib/dao-factory.js

@@ -342,7 +342,7 @@ module.exports = (function() {
 
     if (options.force) {
       return self.drop(options).then(function () {
-        return doQuery();
+        return doQuery().return(self);
       });
     } else {
       return doQuery().return(this)

test/dao-factory.test.js

@@ -1566,13 +1566,13 @@ describe(Support.getTestDialectTeaser("DAOFactory"), function () {
       })
     })
 
-    /*afterEach(function() {
+    afterEach(function() {
       var self = this
 
       return this.sequelize.getQueryInterface().dropTable('posts', { force: true }).then(function() {
         return self.sequelize.getQueryInterface().dropTable('authors', { force: true })
       })
-    })*/
+    })
 
     it('uses an existing dao factory and references the author table', function(done) {
       var self    = this