Only migrate enabled extensions when upgrading

Also remove the Extension::install() and Extension::uninstall()
methods, because they add nothing that can't be done with migrations.

src/Console/UpgradeCommand.php

@@ -68,9 +68,13 @@ class UpgradeCommand extends Command
         $migrator = $extensions->getMigrator();
 
         foreach ($extensions->getInfo() as $extension) {
+            if (! $extensions->isEnabled($extension->name)) {
+                continue;
+            }
+
             $this->info('Upgrading extension: '.$extension->name);
 
-            $extensions->enable($extension->name);
+            $extensions->migrate($extension->name);
 
             foreach ($migrator->getNotes() as $note) {
                 $this->info($note);

src/Support/Extension.php

@@ -15,14 +15,6 @@ use Illuminate\Events\Dispatcher;
 
 class Extension extends ServiceProvider
 {
-    public function install()
-    {
-    }
-
-    public function uninstall()
-    {
-    }
-
     public function listen(Dispatcher $events)
     {
     }

src/Support/ExtensionManager.php

@@ -48,15 +48,11 @@ class ExtensionManager
 
     public function enable($extension)
     {
-        $enabled = $this->getEnabled();
-
-        if (! in_array($extension, $enabled)) {
+        if (! $this->isEnabled($extension)) {
             $enabled[] = $extension;
 
             $class = $this->load($extension);
 
-            $class->install();
-
             $this->migrate($extension);
 
             $this->setEnabled($enabled);
@@ -80,12 +76,10 @@ class ExtensionManager
 
         $class = $this->load($extension);
 
-        $class->uninstall();
-
         $this->migrate($extension, false);
     }
 
-    protected function migrate($extension, $up = true)
+    public function migrate($extension, $up = true)
     {
         $migrationDir = base_path('../extensions/' . $extension . '/migrations');
 
@@ -119,6 +113,11 @@ class ExtensionManager
         $this->config->set('extensions_enabled', json_encode($enabled));
     }
 
+    public function isEnabled($extension)
+    {
+        return in_array($extension, $this->getEnabled());
+    }
+
     protected function load($extension)
     {
         if (file_exists($file = $this->getExtensionsDir() . '/' . $extension . '/bootstrap.php')) {