Remove codecov and coverage testenvs and env var config, unneeded.

tox.ini

@@ -11,27 +11,9 @@ commands =
 	pytest {posargs}
 usedevelop = True
 extras = testing
-setenv =
-	COVERAGE_FILE={toxworkdir}/.coverage.{envname}
 passenv =
 	windir  # required for test_pkg_resources
 
-[testenv:coverage]
-description=Combine coverage data and create report
-deps=coverage
-skip_install=True
-changedir={toxworkdir}
-setenv=COVERAGE_FILE=.coverage
-commands=coverage erase
-         coverage combine
-         coverage {posargs:xml}
-
-[testenv:codecov]
-description=[Only run on CI]: Upload coverage data to codecov
-deps=codecov
-skip_install=True
-commands=codecov -X gcov --file {toxworkdir}/coverage.xml
-
 [testenv:docs]
 extras =
 	docs