Update dependencies

Merge pull request #98 from php-school/fix-php8-support

Try fix php8 support

0.6.0

[0.6.0]

Added

• Support for PHP 7.4 & PHP 8.0
• Modernised code base (static analysis, type hints, phpunit, update dependencies)

Removed

• Support for PHP 7.1 and lower

0.5.1

[0.5.1]

Fixed

• Fix dev dependency issue

0.5.0

[0.5.0]

Fixed

• Updated klein/klein to fix output comparison which causes an exercise to incorrectly fail (#84)

Changed

• Updated to php-school/php-workshop 2.2
• Updated to phpunit/phpunit 5.7

0.4.0

[0.4.0]

Changed

• Updated to php-school/php-workshop 2.0 (#72)

0.3.3

[0.3.3]

Fixed

• Clarified getting started instructions and automatically create first file for students (#70)

0.3.2

[0.3.2]

Fixed

• Fix counting of new lines in exercise 3 (#64)

Changed

• Upgraded hoa/socket to 1.0 (#65)