cordova-common followup patch release July 2018

Followup patch release is wanted to use plist@2 instead of plist@3 dependency to resolve ugly engine warning on deprecated Node.js 4. (Followup to cordova-common patch made in CB-14138)

Following steps at https://github.com/apache/cordova-coho/blob/master/docs/tools-release-process.md (with minor adaptations).