Codeception test adjustments for basic and advanced applications

- Moved everything test-related into `tests` directory. Codeception tests are in `codeception`.
- Removed database module since we're using fixtures and migrations.
- Moved console entry points and bootstrap into `tests/codeception/bin`.
- Adjusted travis build scripts.
- Adjusted documentation to be consistent and reflect changes made.
Removed db module from basic app, renamed _helpers to _support and _logs to _output
Renamed guy classes to actors, fixed phpdoc and code style
Exposed basic app entry URL via codeception.yml, refactored configs of advanced app to read from config and define entry script in a single place
Adjusted test configs structure
Fixed copyright year in batch files
Prefixed constants to avoid possible naming conflicts