Added singleton config and changed module structure

neuroapi/_methods/user.py

@@ -0,0 +1,14 @@
+from aiohttp import ClientSession
+
+from .api_method import ApiMethod
+
+
+class User(ApiMethod):
+    async def get(self, id: str, username: str):
+        payload = {'id': id, 'username': username}
+        async with ClientSession() as session:
+            response = await session.post(
+                self.api_url+'/user/get', data=payload)
+        data = await response.json()
+        if 'statusCode' in data:
+            raise Exception(data['message'])