Removes DummyClasses directory in both spec and Todo
Declares methods as public
Adds and modifies spec/model for Comment

- should belong to one user
Changes testing database to in memory sqlite
Changes Tag spec/model - Updates relationships defined

- Tags have a many-to-many relationship with Tasks
- A Tag does not belong, directly, to a User

@kcunterdeluxe I've got some migrations/tests I'm working on to show this.
Adds 3 migrations - New tables: tags, tasks, and tag_task (rough draft)

- Unmodified since `generate:migration...`
- Needs work

@kchunterdeluxe Let's try and keep one migration per table. We can continually:
    - Edit the migration files
    - Run `migrate:refresh`
Adds migrate_db to phpspec.yml