rewrite logger

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

logger/logger_test.go

@@ -6,13 +6,10 @@ import (
 
 func TestLogger(t *testing.T) {
 	l := NewLogger(WithLevel(TraceLevel))
-	h1 := NewHelper(l).WithFields(map[string]interface{}{"key1": "val1"})
-	h1.Trace("trace_msg1")
-	h1.Warn("warn_msg1")
-
-	h2 := NewHelper(l).WithFields(map[string]interface{}{"key2": "val2"})
-	h2.Trace("trace_msg2")
-	h2.Warn("warn_msg2")
-
-	l.Fields(map[string]interface{}{"key3": "val4"}).Log(InfoLevel, "test_msg")
+	if err := l.Init(); err != nil {
+		t.Fatal(err)
+	}
+	l.Trace("trace_msg1")
+	l.Warn("warn_msg1")
+	l.Fields(map[string]interface{}{"error": "test"}).Info("error message")
 }