feat: add flake8 to pre-commit hooks

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+ignore = E211, E999, F401, W503
+max-doc-length = 72

.pre-commit-config.yaml

@@ -1,5 +1,9 @@
 repos:
-  - repo: https://github.com/pycqa/isort
+  - repo: https://github.com/PyCQA/flake8
+    rev: 3.8.4
+    hooks:
+      - id: flake8
+  - repo: https://github.com/PyCQA/isort
     rev: 5.7.0
     hooks:
       - id: isort

src/system/date.py

@@ -688,13 +688,13 @@ def toMillis(date):
         date (datetime): The date object to convert.
 
     Returns:
-        long: 8-byte integer representing the number of millisecond
+        int: 8-byte integer representing the number of millisecond
             elapsed since January 1, 1970, 00:00:00 UTC (GMT).
     """
     from time import mktime
 
     millis = mktime(date.timetuple()) * 1000 + date.microsecond // 1000
-    return long(millis)
+    return int(millis)
 
 
 def weeksBetween(date_1, date_2):