add database migrations for #6

compass/database/migrations/2017_07_10_231240_database_settings.php

@@ -0,0 +1,33 @@
+<?php
+
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class DatabaseSettings extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('databases', function (Blueprint $table) {
+            $table->string('timezone', 100)->default('UTC');
+            $table->boolean('metric')->default(true);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table('databases', function (Blueprint $table) {
+            $table->dropColumn('timezone');
+            $table->dropColumn('metric');
+        });
+    }
+}