Possibility to change the default configurations for the queue jobs. (#13)

* Add $queue attribute

This code enables me to change the queue name that the JobPipeline will be pushed to.

Now I can do something like this:
```php
JobPipeline::make([
    Jobs\CreateDatabase::class,
    Jobs\MigrateDatabase::class,
    // Jobs\SeedDatabase::class,

    // Your own jobs to prepare the tenant.
    // Provision API keys, create S3 buckets, anything you want!

])->send(function (Events\TenantCreated $event)
{
    return $event->tenant;
})->onQueue('another-queue')
    ->shouldBeQueued()
```

* Add .idea directory to gitignore

* The following methods where added: onConnection, onQueue, delay, tries, shouldBeQueuedOn. The signature of shouldBeQueued was changed too.

* reuse shouldBeQueuedOn

* updating docs

* added timeout

* docs updated

* .phpunit.cache/ added to gitignore

* tests for shouldQueueOn method

* leave only shouldBeQueued method

* update README

* remove unnecessary property declarations

* Delete  jobpipelinetest.json

* add jobpipelinetest.json as a empty file

* update readme

* simplify tests

* improve code

* improve readme

---------

Co-authored-by: Samuel Štancl <samuel@archte.ch>

src/JobPipeline.php

@@ -25,7 +25,10 @@ class JobPipeline implements ShouldQueue
     public $passable;
 
     /** @var bool */
-    public $shouldBeQueued;
+    public bool $shouldBeQueued;
+
+    /** @var string */
+    public string $queue;
 
     public function __construct($jobs, callable $send = null, bool $shouldBeQueued = null)
     {
@@ -50,10 +53,14 @@ class JobPipeline implements ShouldQueue
         return $this;
     }
 
-    public function shouldBeQueued(bool $shouldBeQueued = true)
+    public function shouldBeQueued(bool $shouldBeQueued = true, string $queue = null)
     {
         $this->shouldBeQueued = $shouldBeQueued;
 
+        if ($queue) {
+            $this->queue = $queue;
+        }
+
         return $this;
     }