Appveyor builds failing (pylint, pip, etc.)

[nyanpasu64]

pylint --rcfile=.pylintrc --disable=no-member tests\test_integration.py
Using config file C:\projects\clcache\.pylintrc
************* Module test_integration
C: 24, 0: third party import "import pytest" should be placed before "from clcache import __main__ as clcache" (wrong-import-order)

I patched around this issue on https://github.com/jimbo1qaz/clcache/commits/master (but Appveyor still fails later on.)

codecov.exe : The filename, directory name, or volume label syntax is incorrect.
At line:9 char:1
+ & codecov --no-color -X gcov -F unittests -e PYTHON_INSTALL
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (The filename, d...x is incorrect.:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

https://ci.appveyor.com/project/jimbo1qaz/clcache/build/1.0.7/job/798opi9e23fious7

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I also fixed an issue where pip install -U pip setuptools wheel pip would try to upgrade itself, and be unable to overwrite pip.exe. I changed to the Python-recommended python -m pip install -U pip setuptools wheel.

[Frerich Raabe]

The CI builds seem to work again.