Bump phpunit/phpunit from 3.7.38 to 4.8.28#1

dependabot[bot] wants to merge 1 commit intomasterkcphpug/advent2016:masterfrom

dependabot/composer/phpunit/phpunit-4.8.28kcphpug/advent2016:dependabot/composer/phpunit/phpunit-4.8.28Copy head branch name to clipboard