uses: actions/checkout@v2 (#1779)

* uses: actions/checkout@v2

* fixup! Format Python code with psf/black push

.github/workflows/autoblack.yml

@@ -9,7 +9,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - uses: actions/setup-python@v1
       - run: pip install black
       - run: black --check .

maths/modular_exponential.py

@@ -5,6 +5,8 @@
 """
 
 """Calculate Modular Exponential."""
+
+
 def modular_exponential(base: int, power: int, mod: int):
     """
     >>> modular_exponential(5, 0, 10)

maths/monte_carlo_dice.py

@@ -1,6 +1,7 @@
 import random
 from typing import List
 
+
 class Dice:
     NUM_SIDES = 6