v0.13.0

Setup:

[setup] bump up version 4b23bea

Code:

[add] middleware as selectable response 088c9f7
[change] enable middleware function to define statusCode 18aacab

Tests:

[test] add tests for selectable middleware response c8780b9
[test] update tests for selectable middleware response 16bd252

Documentation:

[doc] add documentation for middleware 363f220
[doc] update documentation for middleware cc3ea5b