reorganize the library into three folders lib, contrib and core

Write unittests with pytest
Make all functions and method signatures as keyword only arguments

tests/unittests/test_account.py

@@ -0,0 +1,20 @@
+import pytest
+from aiomql.lib.account import Account
+
+class TestAccount:
+
+    @classmethod
+    def setup_class(cls):
+        cls.account = Account()
+
+    @pytest.fixture(scope='class', autouse=True)
+    async def refresh(self):
+        await self.account.refresh()
+
+    async def test_connected(self):
+        assert self.account.connected is True
+
+    async def test_account_info(self):
+        acc_info = await self.account.mt5.account_info()
+        assert acc_info.login == self.account.login
+        assert acc_info.server == self.account.server