Refactoring Service Provider to use the boot() method which works for both Laravel and Lumen

[EricTendian]

I am running Lumen, and when I try to use this service provider, the error I get is Call to undefined method MyAppNamespace\Application::booted(). This is occurring because booted() does not exist on \Laravel\Lumen\Application. Additionally, we should not need to register the listener as the service provider has a boot() method.

Thus, this PR uses the boot method for loading the new queue connector. I have tested it manually and verified it works on both Lumen and Laravel. Once this is merged in, it should be backported to 5.3 and 5.2 branches - I would have done so but not sure what your recommended practice is on this.

Besides the service provider update, this also fixes a small typo in the documentation which still references config files within the app directory.

Thanks!

[coveralls]

Coverage decreased (-0.03%) to 98.148% when pulling bf16e71 on EricTendian:master into c1995d3 on squigg:master.

[coveralls]

Coverage decreased (-0.03%) to 98.148% when pulling bf16e71 on EricTendian:master into c1995d3 on squigg:master.

[squigg]

Thanks for this!

I'll merge this in, fix the tests (removing HHVM should do the job, as it's not been supported since Laravel 5.3 anyway), and tag a new version.

Will backport to the other 5.x branches also.