Update license year

Clean up phpunit.xml.dist

Test on different Tarantool versions

Bump minimum PHP version requirement to 7.1 (#14)

* Bump php version to 7.1
* Temporary skip the test for the pecl connector until this PR is merged: tarantool/tarantool-php#134
* Use variadic args in Queue::call()
* Use float type hint for timestamp and interval arguments
* Declare strict types
* Fix scrutinizer fails to parse a coverage file
* Add .php_cs.dist
* Update README.md

Update README.md

Update some integration tests

Ref: tarantool/queue@32ff608

Add option constants (#12)

Add Queue::touch() (#10)

Tweak queues.lua example in README.md

Tweak README.md