travis: stop testing on node v0.6.x as per isaacs/npm#4379
travis: stop testing on node v0.6.x as per isaacs/npm#4379

elaberge/node-zipfile,gravitystorm/node-zipfile,elaberge/node-zipfile,elaberge/node-zipfile,gravitystorm/node-zipfile,gravitystorm/node-zipfile,gravitystorm/node-zipfile,elaberge/node-zipfile