Update code to use guard-phpunit2

Signed-off-by: crynobone <crynobone@gmail.com>
Update to mockery 0.9.0`

Signed-off-by: crynobone <crynobone@gmail.com>
Fixes FatalErrorException being thrown when inheriting abstract method
when it was previously declared in certain PHP 5.3 environment. Closes
orchestral/platform#34.

Signed-off-by: crynobone <crynobone@gmail.com>
Add missing v2.1.1 changelog.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.1'

Signed-off-by: crynobone <crynobone@gmail.com>

Conflicts:
	composer.json