add internals library and slack notifier

[ks6088ts]

What this PR does / why we need it

• refactor: add internals library
• add slack notifier

Which issue(s) this PR fixes:

Fixes #78

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

ORGANIZATION=<organization-name>
REPOSITORY=<repository-name>

git clone [email protected]:$ORGANIZATION/$REPOSITORY.git
cd $REPOSITORY

• Test the code

make ci-test

What to Check

Verify that the following are valid

• ...

Additional Information