Test: Add a mock method to MockContext in order to fix tests error

Can't locate object method "session" via package "t::MockContext::Ok" at
/Users/asami/workspace/perl/board/lib/board/Web/C/Response.pm line 27.
Test: Add tests for loading modules
Test: Add a test for utility class
Add a method that creats MD5 digest from string to utility class
Store hashed password in database
Merge pull request #47 from oguro1021/hashed_password

Store hashed password in database