appveyor: test node v0.12, don't test v0.11
appveyor: test node v0.12, don't test v0.11

pmuellr/node-ffi,skoky/node-ffi,pmuellr/node-ffi,Icenium/node-ffi,skoky/node-ffi,unbornchikken/node-ffi,craigcomstocks/node-ffi,paulcbetts/node-ffi,unbornchikken/node-ffi,lzpfmh/node-ffi,node-ffi/node-ffi,node-ffi/node-ffi,unrealsolver/node-ffi,Icenium/node-ffi,pmuellr/node-ffi,skoky/node-ffi,unrealsolver/node-ffi,Icenium/node-ffi,paulcbetts/node-ffi,craigcomstocks/node-ffi,node-ffi/node-ffi,skoky/node-ffi,node-ffi/node-ffi,pmuellr/node-ffi,paulcbetts/node-ffi,craigcomstocks/node-ffi,unrealsolver/node-ffi,unbornchikken/node-ffi,lzpfmh/node-ffi,Icenium/node-ffi,unbornchikken/node-ffi,craigcomstocks/node-ffi,unrealsolver/node-ffi,lzpfmh/node-ffi,paulcbetts/node-ffi,lzpfmh/node-ffi