Update React Native to 0.61.5

[jtreanor]

This is a draft of the first steps for upgrading the project to React Native 0.61.5

I have focussed on verifying that the CocoaPods patch for RN 0.61.x works correctly (facebook/react-native#25349). Here is what I have done so far:

• Updated RN and associated packages in package.json.
• Made a few small changes to get it to bundle successfully.
• Updated bin/generate-podspecs.sh to work with the new RN version.
• Generated the new podspecs and deleted obsolete ones.

Sister PRs:

• WPAndroid PR: Update gutenberg-mobile to use the Hermes JS runtime WordPress-Android#10997
  Point to the RN 0.61 upgrade in gutenberg-mobile WordPress-Android#10978
• WP-iOS corresponding PR: Update Podfile to support RN-0.61 WordPress-iOS#13116
• Gutenberg PR:
  [RNMobile] Update to RN v0.61 WordPress/gutenberg#19167 [RNmobile] Upgrade to RN 0.61.5 WordPress/gutenberg#19369
• react-native-video fork PR: Changes for gb mobile upgrade to rn 0.61 react-native-video#4
• react-native-svg fork PR: Changes for gb mobile upgrade to rn 0.61 react-native-svg#9

As you can see from the failing CI, there is quite a bit more to do. However, it already successfully builds in WPiOS (see wordpress-mobile/WordPress-iOS#12699).

The biggest outstanding piece of work that I encountered is that gutenberg.xcodeproj will have to be completely overhauled to use CocoaPods. It may be helpful to follow the upgrade helper here.

Update release notes:

• If there are user facing changes, I have added an item to RELEASE-NOTES.txt.

[SergioEstevao]

The biggest outstanding piece of work that I encountered is that gutenberg.xcodeproj will have to be completely overhauled to use CocoaPods. It may be helpful to follow the upgrade helper here.

FYI: I updated the project for this version of RN, basically and the dependencies are now added by cocapods instead of having subprojects. This mean that we now have gutenberg.xcworkspace that needs to be used instead of the .xcodeproj file.

[hypest]

👋 @SergioEstevao, perhaps you have some clue here: I get .../ios/gutenberg/MediaPickCoordinator.swift:4:8: error: cannot load module 'gutenberg' as 'Gutenberg' while trying to run yarn ios. Do we need some extra setup step perhaps?

[hypest]

Also, I'm getting a Ruby setup issue while running yarn ios:

$ yarn ios
yarn run v1.16.0
$ cd ios && (bundle check --path=vendor/bundle > /dev/null || bundle install) && bundle exec pod install
rbenv: bundle: command not found

The `bundle' command exists in these Ruby versions:
  2.3.0
  2.5.5

rbenv: bundle: command not found

The `bundle' command exists in these Ruby versions:
  2.3.0
  2.5.5

error Command failed with exit code 127.

[pinarol]

An update on my comment: since we don't use our fork anymore we are planning do a separate PR to get that fix in.

[hypest]

Found a red screen on Android:

Edit: happening on develop too

1. Add a list block
2. Tap on the "set bullet type to numbers" button in the toolbar
3. 💥

[hypest]

LGTM!

[hypest]

The Android device testsuite is failing on the rotate-and-send-text test which by now is know to be "consistently" flaky so, will go ahead and finish the merge domino.