ui: skip hledger-ui again #376

With the latest change in the package.yaml file, stack does
skip building hledger-ui on windows as intended, however
this causes all-package stack commands to exit with an error.
So yes, on appveyor we must explicitly name the packages to build.

appveyor.yml

@@ -15,7 +15,7 @@ environment:
     STACK_ROOT: "c:\\sr"
 
 test_script:
-- echo "" | stack --no-terminal --install-ghc test
+- echo "" | stack --no-terminal --install-ghc test hledger hledger-web hledger-api
 - stack --local-bin-path . install hledger hledger-web hledger-api
 
 artifacts: