add unit test and etc
add logging
TODO: multiple process and multiple thread while logging well
modified logging a bit, changed the purpose of project, also added the features I want to add.
github test
test for pull request
again for pull request
Merge pull request #1 from junholy/db

Test "Create pull request"
Revert "Merge pull request #1 from junholy/db"

This reverts commit b31f078b62fcfb83c272401d483c500f25889b9c, reversing
changes made to f616f379c669aded59d1c85f4c0075d60db8e9b9.