Add database driver and config module

Signed-off-by: Asai Neko <sugar@sne.moe>

config/default.go

@@ -0,0 +1,15 @@
+package config
+
+var serverDef = server{
+	Address:    ":8000",
+	DebugMode:  false,
+	FileLogger: false,
+}
+
+var databaseDef = database{
+	Type:     "postgres",
+	Host:     "",
+	Name:     "",
+	Username: "",
+	Password: "",
+}