Update to plist@3 WIP FOR MINOR PATCH RELEASE

[brodycj]

Platforms affected

iOS

What does this PR do?

Use plist@3 (3.0.1) dependency to help resolve an ugly NPM install warning (shows up in npm audit)

What testing has been done on this change?

• unit test
• tested in basic Cordova project (initialized using cordova create)

Checklist

• Reported an issue in the JIRA database
• Commit message follows the format: "CB-3232: (android) Fix bug with resolving file paths", where CB-xxxx is the JIRA ID & "android" is the platform affected.
• Added automated test coverage as appropriate for this change.

Other

I would recommend a minor version bump, may need another major version bump to be 100% sure.

[codecov-io]

Codecov Report

Merging #367 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #367   +/-   ##
=======================================
  Coverage   63.99%   63.99%           
=======================================
  Files          14       14           
  Lines        1697     1697           
  Branches      286      286           
=======================================
  Hits         1086     1086           
  Misses        611      611

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[brodycj]

Rebased on #371 (CI testing on Node.js 8 & 10) for WIP TESTING, will be rebased again if #371 is accepted and merged.

[brodycj]

Closing - plist@2 will be used in minor release to avoid ugly engine warning message on Node.js 4