2.0.3 modernise toolchain and supported versions

ci: check coding standards instead of applying them

The coding-standards job ran php-cs-fixer without --dry-run, so it rewrote
the checkout, always exited 0 and pushed the result through
create-pull-request. That step is currently failing on master with a git
400, and it meant a style violation could never fail the build.

Also adds a workflow_dispatch trigger so CI can be started by hand.

2.0.2 use Predis\ClientInterface instead of Predis\Client

use Predis\ClientInterface instead of Predis\Client

2.0.1 support predis 2

support predis 2

2.0.0 PHP 7.2

• cdcbdd1 PHPStan level max (othillo)
• 20b94bd only support actively supported Symfony versions (othillo)
• 1c7cdda Update predis/predis requirement from ~0.8 to ~1.1 (othillo)
• f77479b .mailmap for changelog (othillo)
• 1aff63a updated Travis CI build status badge (othillo)
• 02a243a added license (othillo)
• f5d5f27 PHPUnit 8 (othillo)
• 925582a PHPStan level 5 (othillo)
• 989581f adopted Broadway coding standard (othillo)
• 41a4497 Makefile (othillo)
• 47382be only support actively supported PHP versions (othillo)
• 306b651 upgrade to PHPUnit 7 (othillo)
• 46a0b10 only test actively supported PHP versions (othillo)
• 66f3b4b Tests on php 7.3 (othillo)
• 12fa8e3 Fix example in from-array.php (Alexandr Mazur)
• 8117a8e fix yaml example (#49) (othillo)
• b8f230f Add NotInSet operator (Andrew Warren-Love)
• 5b44d92 Enhancement: Add PHP 7.1 and 7.2 to Travis build matrix (#48) (othillo)
• 19a1aa9 Add capability to retrieve one Toggle from ToggleManager

1.1.1: Merge pull request #43 from gabriel-caruso/phpunit

Use PHPUnit\Framework\TestCase instead of PHPUnit_Framework_TestCase

1.1.0: Merge pull request #41 from rplansky/has-intersection-operator

New has-intersection operator

1.0.2: Merge pull request #39 from Trekels/master

Readability and code quality improvements