appveyor.yml: build zlib together
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56231 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
appveyor.yml: build zlib together
build within the build process.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56231 b2dd03c8-39d4-4d8f-98ff-823fe69b080e