* Bump PHP version to 7.1 in readme
* Bump PHP version to 7.1 in class templates
* Remove HHVM from Travis CI config
PHPUnit dropped support of hhvm, so build unlikely will pass tests.
https://github.com/sebastianbergmann/phpunit/issues/3320#issuecomment-426325646
* Remove sudo: false from Travis-CI config
Official doc recommendation:
https://docs.travis-ci.com/user/reference/trusty/#container-based-infrastructure
* Change tested versions to 7.1, 7.2 in Travis-CI
* Remove PHP_CodeSniffer from dev dependencies
There is another linter(PHP CS Fixer) which is fully configured while
CodeSniffer isn't configured at all.
* Use caret instead of tilde in dependencies
^2.12 equals (>= 2.12.0 && <3.0.0) while ~2.12 is (>=2.12.0 && <2.13.0)
* Refresh samples
* Use appDescription in composer.mustache
* Update petstore files
* More updated php petstore files
* Yet another updated php petstore file
* Use "{{{appDescription}}}" instead of "{{appDescription}}"
