Removed random from test imports. Also some linting.

tests/test_umbral.py

@@ -1,14 +1,12 @@
 import pytest
 
 from umbral import umbral, keys
-import random
-
-# (N,threshold)
-from umbral.umbral import Capsule
-from umbral.point import Point
 from umbral.bignum import BigNum
+from umbral.point import Point
+from umbral.umbral import Capsule
 
 parameters = [
+    # (N,threshold)
     (1, 1),
     (6, 1),
     (6, 4),
@@ -84,7 +82,6 @@ def test_m_of_n(N, threshold):
     priv_bob = pre.gen_priv()
     pub_bob = pre.priv2pub(priv_bob)
 
-
     sym_key, capsule = pre._encapsulate(pub_alice)
     kfrags, vkeys = pre.split_rekey(priv_alice, pub_bob, threshold, N)
 
@@ -101,7 +98,6 @@ def test_m_of_n(N, threshold):
     # assert capsule.is_openable_by_bob()  # TODO: Is it possible to check here if >= m cFrags have been attached?
     capsule.open(pub_bob, priv_bob, pub_alice)
 
-
     sym_key_2 = pre._decapsulate_reencrypted(pub_bob, priv_bob, pub_alice, capsule)
     assert sym_key == capsule.contents
 
@@ -167,6 +163,7 @@ def test_capsule_serialization():
                                             umbral.UmbralParameters().curve)
     assert new_capsule.original_components() == capsule.original_components()
 
+
 def test_reconstructed_capsule_serialization():
     pre = umbral.PRE(umbral.UmbralParameters())