- drop support php < 7.2
- update phpunit to 7.5
- add strict types in all files
- add return type and argument type hinting in all files
- bump copyright to 2019

This is to add return type and type hinting support.
Everything above is optional. This way we can make sure,
we only get the correct types without the need to check them.

Also drop symfony/console 2 support for dev requirements.

Restructuring documentation and give it some love

Updates the requirements on [slevomat/coding-standard](https://github.com/slevomat/coding-standard) to permit the latest version.
- [Release notes](https://github.com/slevomat/coding-standard/releases)
- [Commits](slevomat/coding-standard@4.8.0...6.1.5)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Upgrade to GitHub-native Dependabot

…ing-standard-tw-6.1

Update slevomat/coding-standard requirement from ^4.8 to ^6.1

Updates the requirements on [phpstan/phpstan](https://github.com/phpstan/phpstan) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Commits](phpstan/phpstan@0.11...0.12.88)

Signed-off-by: dependabot[bot] <support@github.com>

…tan-tw-0.12.88

Update phpstan/phpstan requirement from ^0.11.0 to ^0.12.88