MNT Update python dependencies (#753)

Co-authored-by: Roman Yurchak <rth.yurchak@gmail.com>

packages/attrs/meta.yaml

@@ -1,11 +1,11 @@
 package:
   name: attrs
-  version: 19.3.0
+  version: 20.1.0
 source:
   patches:
   - patches/use-dummy-threading.patch
-  sha256: f7b7ce16570fe9965acd6d30101a28f62fb4a7f9e926b3bbc9b61f8b04247e72
-  url: https://files.pythonhosted.org/packages/98/c3/2c227e66b5e896e15ccdae2e00bbc69aa46e9a8ce8869cc5fa96310bf612/attrs-19.3.0.tar.gz
+  sha256: 0ef97238856430dcf9228e07f316aefc17e8939fc8507e18c6501b761ef1a42a
+  url: https://files.pythonhosted.org/packages/c4/d4/c2b5232ecfc0783c697a81c13efc53a4fe285d4e2c00e0d8aed90495fade/attrs-20.1.0.tar.gz
 test:
   imports:
   - attr

packages/more-itertools/meta.yaml

@@ -1,9 +1,9 @@
 package:
   name: more-itertools
-  version: 8.4.0
+  version: 8.5.0
 source:
-  sha256: 68c70cc7167bdf5c7c9d8f6954a7837089c6a36bf565383919bb595efb8a17e5
-  url: https://files.pythonhosted.org/packages/67/4a/16cb3acf64709eb0164e49ba463a42dc45366995848c4f0cf770f57b8120/more-itertools-8.4.0.tar.gz
+  sha256: 6f83822ae94818eae2612063a5101a7311e68ae8002005b5e05f03fd74a86a20
+  url: https://files.pythonhosted.org/packages/d6/03/37d7c431c4c1c17507fb7b89240ddb7be70f2027277960d525f1679363c1/more-itertools-8.5.0.tar.gz
 test:
   imports:
   - more_itertools

packages/pluggy/meta.yaml

@@ -1,12 +1,9 @@
 package:
   name: pluggy
-  version: 0.7.1
-
+  version: 0.13.1
 source:
-  url: https://pypi.io/packages/source/p/pluggy/pluggy-0.7.1.tar.gz
-  sha256: 95eb8364a4708392bae89035f45341871286a333f749c3141c20573d2b3876e1
-
-
+  sha256: 15b2acde666561e1298d71b523007ed7364de07029219b604cf808bfa1c765b0
+  url: https://files.pythonhosted.org/packages/f8/04/7a8542bed4b16a65c2714bf76cf5a0b026157da7f75e87cc88774aa10b14/pluggy-0.13.1.tar.gz
 test:
   imports:
-    - pluggy
+  - pluggy