Test Xcode 10 (#21324)
Test Xcode 10 (#21324)

Summary:
This also fixes an issue with tagged commit Circle CI jobs, and avoids running the `publish_npm_package` on every commit. The new config ignores commits on *all branches*, but should still catch git tags.
Pull Request resolved: https://github.com/facebook/react-native/pull/21324

Differential Revision: D10041629

Pulled By: hramos

fbshipit-source-id: 9b3295b5fcd614c67a8838ffd49c6a5d6ae7fd86

myntra/react-native,pandiaraj44/react-native,facebook/react-native,hoangpham95/react-native,exponentjs/react-native,hammerandchisel/react-native,facebook/react-native,myntra/react-native,exponent/react-native,pandiaraj44/react-native,javache/react-native,facebook/react-native,arthuralee/react-native,exponent/react-native,javache/react-native,pandiaraj44/react-native,arthuralee/react-native,myntra/react-native,exponentjs/react-native,hoangpham95/react-native,exponentjs/react-native,janicduplessis/react-native,javache/react-native,exponentjs/react-native,janicduplessis/react-native,hammerandchisel/react-native,exponent/react-native,janicduplessis/react-native,janicduplessis/react-native,pandiaraj44/react-native,exponent/react-native,hammerandchisel/react-native,hoangpham95/react-native,myntra/react-native,exponent/react-native,javache/react-native,hammerandchisel/react-native,javache/react-native,hammerandchisel/react-native,exponent/react-native,exponent/react-native,exponentjs/react-native,facebook/react-native,pandiaraj44/react-native,arthuralee/react-native,arthuralee/react-native,hoangpham95/react-native,janicduplessis/react-native,javache/react-native,hammerandchisel/react-native,exponentjs/react-native,hoangpham95/react-native,myntra/react-native,javache/react-native,facebook/react-native,facebook/react-native,hoangpham95/react-native,exponent/react-native,hoangpham95/react-native,janicduplessis/react-native,myntra/react-native,janicduplessis/react-native,hammerandchisel/react-native,hammerandchisel/react-native,hoangpham95/react-native,exponentjs/react-native,myntra/react-native,myntra/react-native,janicduplessis/react-native,pandiaraj44/react-native,facebook/react-native,pandiaraj44/react-native,pandiaraj44/react-native,arthuralee/react-native,facebook/react-native,exponentjs/react-native,javache/react-native,facebook/react-native,myntra/react-native,javache/react-native