Merge pull request #2705 from bsipocz/MAINT_no_codecov

MAINT: remove unused and otherwise unsupported dependency

Author: bsipocz

tox.ini

@@ -40,7 +40,6 @@ deps =
     oldestdeps: beautifulsoup4==4.8
     oldestdeps-alldeps: mocpy==0.9
 
-    cov: codecov
     online: pytest-rerunfailures
 
 extras =