Try to fix tests in appveyor build.

[ObiWahn]

Locally the tests build and run successfully in VisualStudio.

When using PowerShell locally the test output is the same as with appveyor:

test 1
    Start 1: test-ext-logging_run
1: Test command: C:\projects\logging\build_dir\tests\Release\test-ext-logging.exe
1: Test timeout computed to be: 1500
1/1 Test #1: test-ext-logging_run .............Exit code 0xc0000135
***Exception:   0.17 sec
0% tests passed, 1 tests failed out of 1