feat: do not fail when .env is missing (#10)

config.go

@@ -1,6 +1,7 @@
 package memogram
 
 import (
+	"os"
 	"github.com/caarlos0/env"
 	"github.com/joho/godotenv"
 	"github.com/pkg/errors"
@@ -12,10 +13,13 @@ type Config struct {
 }
 
 func getConfigFromEnv() (*Config, error) {
-	err := godotenv.Load(".env")
+	envFileName := ".env"
+	if _, err := os.Stat(envFileName); err == nil {
+		err := godotenv.Load(envFileName)
 		if err != nil {
 			panic(err.Error())
 		}
+	}
 
 	config := Config{}
 	if err := env.Parse(&config); err != nil {