[enh] #91 fix code to comply with mypy and pylint

Remove one pylint alert

Makefile

@@ -17,4 +17,4 @@ mypy:
 
 # check code errors
 pylint:
-	pylint --disable=C,R0913,R0903,R0902,R0914,R0912,R0915 --enable=C0121,C0202,C0321 --jobs=0 duniterpy/
+	pylint --disable=C,R0913,R0903,R0902,R0914,R0912,R0915,W0613 --enable=C0121,C0202,C0321 --jobs=0 duniterpy/

duniterpy/api/client.py

@@ -236,12 +236,13 @@ class Client:
             await parse_response(response, schema)
 
         # return the chosen type
+        result = response  # type: Any
         if rtype == RESPONSE_TEXT:
-            response = await response.text()
+            result = await response.text()
         elif rtype == RESPONSE_JSON:
-            response = await response.json()
+            result = await response.json()
 
-        return response
+        return result
 
     async def post(self, url_path: str, params: dict = None, rtype: str = RESPONSE_JSON, schema: dict = None) -> Any:
         """
@@ -267,12 +268,13 @@ class Client:
             await parse_response(response, schema)
 
         # return the chosen type
+        result = response  # type: Any
         if rtype == RESPONSE_TEXT:
-            response = await response.text()
+            result = await response.text()
         elif rtype == RESPONSE_JSON:
-            response = await response.json()
+            result = await response.json()
 
-        return response
+        return result
 
     def connect_ws(self, path: str) -> _WSRequestContextManager:
         """

duniterpy/documents/transaction.py

@@ -339,7 +339,7 @@ class UnlockParameter:
         :param parameter: Parameter string
         :return:
         """
-        result = None
+        result = None  # type: Optional[Union[SIGParameter, XHXParameter]]
         sig_param = SIGParameter.from_parameter(parameter)
         if sig_param:
             result = sig_param