Introduce sequelize migrations to create and migrate database tables and removed database scripts. See http://sequelizejs.com/docs/latest/migrations

Created seeds to initialize database with dummy tasks.
Introduce config module to handle configurations per environment. See https://github.com/lorenwest/node-config
Updated README.md to reflect changes.

config/database.json

@@ -0,0 +1,17 @@
+{
+  "development": {
+    "dialect": "sqlite",
+    "storage": "db/development.sqlite"
+  },
+  "test": {
+    "dialect": "sqlite",
+    "storage": "db/test.sqlite"
+  },
+  "production": {
+    "username": "root",
+    "password": null,
+    "database": "database_production",
+    "host": "127.0.0.1",
+    "dialect": "mysql"
+  }
+}