update to use sqlalchemy

- change from mysql-connector-python to sqlalchemy
    - allow for connection to sqlite3, mysql, mariadb, postgres, and
oracle databases
- change `DATE` columns to `DATETIME` type
- add WHO columns
- install database connectors and required packages

.gitignore

@@ -1,3 +1,4 @@
 .env
 env/*
 .git
+db/*