Update to phpunit 4.
Enable strict phpunit tests.
Use PHPUnit as a library rather than via CLI.

This makes things less fragile.  See dominionenterprises/util-php#32 for
more details.
Merge pull request #39 from nubs/phpunit-as-a-library

Access PHPUnit as a library for gathering report
Remove clover.xml from gitignore.
Use the full path for code coverage.
Use phpcs as a library.