use latest modules

Author: yattom

requirements.txt

@@ -1,9 +1,13 @@
+appdirs==1.4.4
 cov-core==1.15.0
-coverage==5.2
-execnet==1.7.1
-py==1.9.0
-pytest==5.4.3
-pytest-cov==2.10.0
-pytest-xdist==1.32.0
-tox==2.7.0
-virtualenv==20.0.25
+coverage==5.5
+distlib==0.3.1
+execnet==1.8.0
+filelock==3.0.12
+iniconfig==1.1.1
+py==1.10.0
+pytest-cov==2.11.1
+pytest-xdist==2.2.1
+pytest==6.2.4
+tox==3.23.1
+virtualenv==20.4.6