v2.8.0

This release removes support for HHVM and increases the minimum
supported PHP version to PHP 7.1.0.

In addition to that, code has been cleaned up to remove quirks
related to previous PHP version support handling.

We introduced static analysis in our continuous integration
pipeline by integrating PHPStan
with the build process.

In addition to these changes there were multiple minor bugfixes
around the test suite, PHPUnit compatibility, the Debug::export()
utility and docBlock/documentation correctness.

Total issues resolved: 22

• 716: Minor docblock spelling correction in AbstractClassMetadataFactory thanks to @gnat42
• 718: Removed empty /lib/vendor directory from auto-generated ZIP archives thanks to @mlocati
• 757: Bumped phpunit version to 5.7 thanks to @gabbydgab
• 760: Fixed typo in ManagerRegistry documentation thanks to @aledeg
• 765: Integrated PHPStan and discovered related fixes thanks to @ondrejmirtes
• 769: Specify array type in ClassMetadataFactory::getAllMetadata() docblock thanks to @soullivaneuh
• 770: ProxyFactory may generate invalid proxies with no error thanks to @theofidry
• 771: ProxyGenerator: Disallow creating proxies for abstract and final classes thanks to @Majkl578
• 772: Invalid data provider in the ObjectManagerDecoratorTest thanks to @Ocramius
• 773: #772 Fixed ObjectManagerDecoratorTest, which wasn't considering void hints thanks to @ondrejmirtes
• 776: ProxyGenerator has a typo in a docblock annotation, causing annotation reading to crash thanks to @alu
• 777: #776 Fix typo in ProxyGenerator docblock annotation thanks to @Majkl578
• 778: Fix return type docblock for EventManager#dispatchEvent() thanks to @ostrolucky
• 781: Removed dead links to the previous JIRA-based issue tracker thanks to @fridde
• 785: Dropped PHP 5.x and 7.0 support - minimum of PHP 7.1 requirement thanks to @Majkl578
• 789: Removed redundant isset() + empty() check in EventManager#hasListeners() thanks to @ostrolucky
• 790: Removing isset() checks before unset() calls in EventManager#removeEventListener() thanks to @ostrolucky
• 791: Removed always true execution path conditional from StaticReflectionParser thanks to @ostrolucky
• 793: Updated PHPStan dev dependency to 0.7 thanks to @ondrejmirtes
• 796: Dropped HHVM support thanks to @lcobucci
• 798: Removed quirks for unsupported PHP versions in Proxy code generation thanks to @Majkl578
• 802: #386 - Simplifying Debug::export() so that runtime properties are also considered thanks to @ostrolucky