Streamline QA tools, dependencies

- Removed coveralls support (service does not work)
- Replace check-cs.sh with inline `--config-file` option for php-cs-fixer
- Remove psr0 check for php-cs-fixer (we use psr4)
- Added contribution guide
- Removed zendframework dependency and replaced with more specific component
  dependencies
Merge branch 'feature/streamline-tools'

Streamline QA tools and dependencies; add contribution guide.