added user independent sections and started db migration work

pkg/core/helper.go

@@ -0,0 +1,11 @@
+package core
+
+// Contains checks if slice a contains string str
+func Contains(str string, a []string) (int, bool) {
+	for i, s := range a {
+		if s == str {
+			return i, true
+		}
+	}
+	return -1, false
+}