Try to make appveryor more verbose during tests.

ObiWahn · ObiWahn · commit e1085f43c44d · 2020-02-02T20:20:14.000+01:00
diff --git a/.appveyor.yml b/.appveyor.yml
@@ -38,4 +38,4 @@ build_script:
   - cmake --build . --config "%CONFIGURATION%"
 
 test_script:
-  - ctest -C "%CONFIGURATION%" --output-on-failure
+  - ctest -C "%CONFIGURATION%" --verbose
