Update composer to require Fixture 1.0.0.

Updated composer.json to require Fixture 1.0.0.
Updated FixtureL4ServiceProvider to be compatible with Fixture 1.0.0.
Create Service Provider test.

Created a behavior test for the FixtureL4ServiceProvider to ensure that
it can properly register an instance of fixture with the application
container.
Rename test file.

Renamed the ServiceProviderTest.php to FixtureL4ServiceProviderTest.php
Update documentation.

Updated the readme documentation.
Merge branch 'master' of github.com:CodeSleeve/fixture-l4

Conflicts:
	README.md