Update some dependencies

Author: nedbat

requirements/dev.pip

@@ -4,18 +4,18 @@
 # Requirements for doing local development work on coverage.py.
 # https://requires.io/github/nedbat/coveragepy/requirements/
 
-pip==19.3.1
-virtualenv==16.7.8
+pip==20.0.2
+virtualenv==16.7.9
 
-pluggy==0.13.0
+pluggy==0.13.1
 
 # PyPI requirements for running tests.
 -r tox.pip
 -r pytest.pip
 
 # for linting.
 greenlet==0.4.15
-pylint==2.4.3
+pylint==2.4.4
 check-manifest==0.40
 readme_renderer==24.0
 

requirements/tox.pip

@@ -2,6 +2,6 @@
 # For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
 
 # The version of tox used by coverage.py
-tox==3.14.1
+tox==3.14.3
 # Adds env recreation on requirements file changes.
 tox-battery==0.5.1

tox.ini

@@ -15,7 +15,7 @@ deps =
     # Check here for what might be out of date:
     #   https://requires.io/github/nedbat/coveragepy/requirements/
     -r requirements/pytest.pip
-    pip==19.3.1
+    pip==20.0.2
     setuptools==41.4.0
     # gevent 1.3 causes a failure: https://github.com/nedbat/coveragepy/issues/663
     py{27,35,36}: gevent==1.2.2