Add support for viewing SFTP password in panel

requested in #74
closes #74

database/migrations/2016_09_02_190647_add_sftp_password_storage.php

@@ -0,0 +1,31 @@
+<?php
+
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class AddSftpPasswordStorage extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('servers', function (Blueprint $table) {
+            $table->text('sftp_password')->after('username')->nullable();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('servers', function (Blueprint $table) {
+            $table->dropColumn('sftp_password');
+        });
+    }
+}