Update phpunit dependency

GitHub #1 - Improvements to readme, include PHP 7 in builds

Merge pull request #63 from martinlindhe/master

Remove 512-byte limit of message size

GitHub #62 - Add application limitations to readme

GitHub #61 - Add note for how to cancel emergency

GitHub #60 - Add lowest priority class

GitHub #58 - Spaces

Merge pull request #50 from sqmk/develop

Develop

Merge pull request #46 from sqmk/develop

GitHub #34 - Add notes about using CLI script

Merge pull request #31 from sqmk/develop

Merge pull request #30 from sqmk/master