setup postgres for travis + use postgres user for local tests

.travis.yml

 before_script:
   - "mysql -e 'create database sequelize_test;'"
+  - "psql -c 'create database sequelize_test;' -U postgres"
   - "npm install"
 
 script:

spec-jasmine/config/config.js

@@ -16,6 +16,7 @@ module.exports = {
 
   postgres: {
     database: 'sequelize_test',
+    username: "postgres",
     port: 5432
   }
 }