Set up unit test.

[dhmoon91]

Let's setup unit test for rank command.

Requirements;

• Record sample response data from riot API request.
• check output matches against snapshot of data. Create new test run command into new .yml that gets triggered upon new push.

[HelloFive]

Lesson learned:

• How to mock API calls (from https://changhsinlee.com/pytest-mock/)
• Postgres does not rollback advances in a sequence even if the sequence is used in a transaction which is rolled back. (from https://stackoverflow.com/a/12443800)
• Could not use SAVEPOINT or rollback() since change was already commited (from https://docs.sqlalchemy.org/en/14/orm/session_transaction.html#using-savepoint)
• Could not use pg_dump or pg_dumpall to backup and restore DB since these commands to not Truncate Table back to empty status (from https://www.postgresql.org/docs/8.3/backup-dump.html)

Solution was to create separate DB for test, and TRUNCATE summoners table after test is done

[HelloFive]

Closing as PR has been merged