remove engines.npm from package.json; closes #3073
remove engines.npm from package.json; closes #3073

mochajs/mocha,boneskull/mocha,boneskull/mocha,mochajs/mocha,igwejk/mocha,adamgruber/mocha,hoverduck/mocha,mochajs/mocha,outsideris/mocha,hoverduck/mocha,hoverduck/mocha,hoverduck/mocha,igwejk/mocha,adamgruber/mocha,boneskull/mocha,outsideris/mocha,adamgruber/mocha