Changes configuration

Author: JJ

.appveyor.yml

@@ -39,11 +39,7 @@ install:
  - SET PATH=C:\rakudo\bin;C:\rakudo\share\perl6\site\bin;%PATH%
  - ps: refreshenv
  - perl6 -v
-# install the target distribution's dependencies. You'll need to
-# maintain your META6.json file in the top-level directory
- - zef --verbose install .
-# change back to the target project's clone folder.
-# Now we should be ready to run the tests
+ - zef install --deps-only .
  - cd %APPVEYOR_BUILD_FOLDER%
 
 build: off