tests: add first test for auth

tests/testauthmanager.h

@@ -0,0 +1,26 @@
+#ifndef TESTAUTHMANAGER_H
+#define TESTAUTHMANAGER_H
+
+#include "authmanager.h"
+#include <QObject>
+#include <QTest>
+
+class TestAuthManager : public QObject
+{
+  Q_OBJECT
+
+public:
+  explicit TestAuthManager(QObject *parent = nullptr);
+
+private slots:
+  void add();
+
+  void testSignIn();
+
+signals:
+
+private:
+  AuthManager *m_authManager;
+};
+
+#endif // TESTAUTHMANAGER_H