Test Alpha on PHP7 and fix any resulting issues

[alphadevx]

No description provided.

[alphadevx]

This should include setting up PHP7 build on Travis CI.

[alphadevx]

It is possible to install PHP7 in parallel to PHP5.6 locally on Fedora, notes are here:

http://blog.remirepo.net/pages/PECL-extensions-RPM-status

And here:

http://blog.remirepo.net/post/2015/03/25/PHP-7.0-as-Software-Collection

[alphadevx]

So it seems that "String" is a reserved word in PHP 7, resulting in the following fatal error:

PHP message: PHP Fatal error: Cannot use Alpha\Model\Type\String as String because 'String' is a special class name in...

Ref: http://php.net/manual/en/reserved.other-reserved-words.php

[alphadevx]

Moving this to a new 3.0.0 release as the upgrade to PHP 7 will force backwards-compatibility breaking changes, e.g. renaming our core String class to something else.

[alphadevx]

PHP unit tests are now failing immediately due to this error:

vendor/bin/phpunit test --stop-on-failure PHP Fatal error: Cannot use Alpha\Model\Type\String as String because 'String' is a special class name in /home/john/Git/alpha/test/Alpha/Test/Model/ActiveRecordTest.php on line 15

The first thing I will try is to rename Alpha\Model\Type\String to Alpha\Model\Type\SmallText to try to fix the tests.