Add codecov support to AppVeyor and remove coveralls

tox.ini

@@ -18,14 +18,14 @@ envlist =
 
 [testenv]
 commands =
-    {env:_PYTEST_TOX_COVERAGE_RUN:} pytest --lsof -ra {env:_PYTEST_TEST_OPTS:} {posargs:testing}
-    coverage: coverage report -m --skip-covered
+    {env:_PYTEST_TOX_COVERAGE_RUN:} pytest --lsof -ra {posargs:testing}
+passenv = USER USERNAME
 setenv =
+    # configuration if a user runs tox with a "coverage" factor, for example "tox -e py36-coverage"
     coverage: _PYTEST_TOX_COVERAGE_RUN=coverage run -m
     coverage: _PYTEST_TOX_EXTRA_DEP=coverage-enable-subprocess
     coverage: COVERAGE_FILE={toxinidir}/.coverage
     coverage: COVERAGE_PROCESS_START={toxinidir}/.coveragerc
-passenv = USER USERNAME
 deps =
     hypothesis>=3.56
     nose
@@ -56,9 +56,8 @@ deps =
     nose
     hypothesis>=3.56
     {env:_PYTEST_TOX_EXTRA_DEP:}
-changedir=testing
 commands =
-    {env:_PYTEST_TOX_COVERAGE_RUN:} pytest -n8 -ra {posargs:.}
+    {env:_PYTEST_TOX_COVERAGE_RUN:} pytest -n8 -ra {posargs:testing}
 
 [testenv:py36-xdist]
 deps = {[testenv:py27-xdist]deps}
@@ -177,21 +176,6 @@ commands =
     {envpython} create_executable.py
     {envpython} tox_run.py
 
-
-[testenv:coveralls]
-passenv = CI TRAVIS TRAVIS_* COVERALLS_REPO_TOKEN
-usedevelop = True
-changedir = .
-deps =
-    {[testenv]deps}
-    coveralls
-    codecov
-commands =
-    coverage run -m pytest testing
-    coverage report -m
-    coveralls
-    codecov
-
 [testenv:release]
 decription = do a release, required posarg of the version number
 basepython = python3.6