[test] Added tests for service as middlewares   * Adds tests for chaining services   * Covers basic API and usage
[test] Added tests for service as middlewares
  * Adds tests for chaining services
  * Covers basic API and usage
Stackvana/stack,Stackvana/stack,Stackvana/stack,Stackvana/stack,Stackvana/stack,Stackvana/stack