Specifically look for cert files in secured() method.

Fixes #1210

Author: mattstauffer

cli/Valet/Site.php

@@ -477,7 +477,9 @@ public function replaceOldLoopbackWithNew($siteConf, $old, $new)
     public function secured()
     {
         return collect($this->files->scandir($this->certificatesPath()))
-                    ->map(function ($file) {
+                    ->filter(function ($file) {
+                        return ends_with($file, ['.key', '.csr', '.crt', '.conf']);
+                    })->map(function ($file) {
                         return str_replace(['.key', '.csr', '.crt', '.conf'], '', $file);
                     })->unique()->values()->all();
     }

tests/SiteTest.php

@@ -787,7 +787,7 @@ public function test_it_returns_secured_sites()
         $files = Mockery::mock(Filesystem::class);
         $files->shouldReceive('scandir')
             ->once()
-            ->andReturn(['helloworld.tld.crt']);
+            ->andReturn(['helloworld.tld.crt', '.DS_Store']);
 
         swap(Filesystem::class, $files);