Added clear activity/revision commands. Cleaned commands.

Added testing to cover each command.
Removed example laravel inspire command.
Standardised command names to be behind 'bookstack' naming.
In reference to #320.

app/Console/Commands/ClearRevisions.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace BookStack\Console\Commands;
+
+use BookStack\PageRevision;
+use Illuminate\Console\Command;
+
+class ClearRevisions extends Command
+{
+    /**
+     * The name and signature of the console command.
+     *
+     * @var string
+     */
+    protected $signature = 'bookstack:clear-revisions
+                            {--a|all : Include active update drafts in deletion}
+                            ';
+
+    /**
+     * The console command description.
+     *
+     * @var string
+     */
+    protected $description = 'Clear page revisions';
+
+    protected $pageRevision;
+
+    /**
+     * Create a new command instance.
+     *
+     * @param PageRevision $pageRevision
+     */
+    public function __construct(PageRevision $pageRevision)
+    {
+        $this->pageRevision = $pageRevision;
+        parent::__construct();
+    }
+
+    /**
+     * Execute the console command.
+     *
+     * @return mixed
+     */
+    public function handle()
+    {
+        $deleteTypes = $this->option('all') ? ['version', 'update_draft'] : ['version'];
+        $this->pageRevision->newQuery()->whereIn('type', $deleteTypes)->delete();
+        $this->comment('Revisions deleted');
+    }
+}