fixes #1913

fixed Markdown::process() to make it compatible with parent declaration.

no need to download codeception via composer when phar is used.
fixes #1913

meet the AR interface requirements.

Removed error-block HTML class and related styles and used Bootstrap3 standard practice about errors instead

Fixes #1827: Debugger toolbar is loaded twice if an action is calling `run()` to execute another action

1. It results in much smaller download and takes less disk space (25MB instead of 180MB for yii-basic + dependencies).
2. It requires less utilities to be installed (no VCS binaries required).
3. It takes less time to install dependencies.

also ignore tests and vendor