Update CI config and add Python 3.7

[hackebrot]

🤖

[hackebrot]

Looks like for several test jobs on AppVeyor pytest fails to detect pytest-cookies even though it installs successfully 🤖

py36 installed: [...] pytest==4.5.0,pytest-cookies==0.3.0
py36 run-test: commands[0] | pytest tests
========================= test session starts =========================
platform win32 -- Python 3.6.8, pytest-4.5.0, py-1.8.0, pluggy-0.11.0
cachedir: .tox\py36\.pytest_cache
rootdir: C:\projects\pytest-cookies
collected 15 items
tests\test_cookies.py FFFFFFFFFFFFF                              [ 86%]
tests\test_help_message.py F                                     [ 93%]
tests\test_user_config.py F                                      [100%]

The log for Python 3.7 shows that enabling the plugin works? 😕

py37 installed: [...] pytest==4.5.0,pytest-cookies==0.3.0
py37 run-test: commands[0] | pytest tests
========================= test session starts =========================
platform win32 -- Python 3.7.3, pytest-4.5.0, py-1.8.0, pluggy-0.11.0
cachedir: .tox\py37\.pytest_cache
rootdir: C:\projects\pytest-cookies
plugins: cookies-0.3.0
collected 15 items
tests\test_cookies.py .............                              [ 86%]
tests\test_help_message.py .                                     [ 93%]
tests\test_user_config.py .                                      [100%]

[hackebrot]

Setting download = true in tox did the trick! 🤷‍♂

[hackebrot]

See pytest-dev/pytest#5222 (comment)