Fix React Native 0.61 support

[brody4hire]

• test generated module & generated view module with example on Android & iOS on React Native 0.61-rc 0.61.1(+)
• update documentation
• Check (again) for Gradle updates from 0.61-stable
• fix Android view (View does not build on Android with React Native 0.60(+) #29)
• fix generated iOS example (fix generated iOS example on React Native 0.60(+) #99)
• update default example react-native version, likely to react-native@latest (this is already part of proposal in PR [wip/???] drop react native 0.59 support #130)
• consider dropping react-native 0.59 support (see issue [...] drop React Native 0.59 support #132 & my proposal in PR [wip/???] drop react native 0.59 support #130)
• consider option to configure minimum react-native version (as proposed in PR [wip/???] drop react native 0.59 support #130)
• Android build.gradle updates from 0.61-stable (PR [WIP] Android build.gradle updates from 0.61-stable #107)

[davidpfahler]

So just to clarify: create-react-native-module does not work with latest react-native? I tried to create a Native Module with it following the official guides and get the following errors when react-native run-ios:

error React Native CLI uses autolinking for native dependencies, but the following modules are linked manually: 
  - react-native-core-ml (to unlink run: "react-native unlink react-native-core-ml")
This is likely happening when upgrading React Native from below 0.60 to 0.60 or above. Going forward, you can unlink this dependency via "react-native unlink <dependency>" and it will be included in your app automatically. If a library isn't compatible with autolinking, disregard this message and notify the library maintainers.
Read more about autolinking: https://github.com/react-native-community/cli/blob/master/docs/autolinking.md
error Could not find the following native modules: react-native-core-ml. Did you forget to run "pod install" ?

When I then cd ios; pod install:

Detected React Native module pod for react-native-core-ml
Analyzing dependencies
[!] CocoaPods could not find compatible versions for pod "react-native-core-ml":
  In Podfile:
    react-native-core-ml (from `../node_modules/react-native-core-ml`)

Specs satisfying the `react-native-core-ml (from `../node_modules/react-native-core-ml`)` dependency were found, but they required a higher minimum deployment target.

In the simulator:

error: bundling failed: Error: Unable to resolve module `warnOnce` from `node_modules/react-native-core-ml/node_modules/react-native/Libraries/react-native/react-native-implementation.js`: warnOnce could not be found within the project.

Is this expected behavior at this point in time?

[zivchen]

+1
Same error
"react-native": "0.61.5"

[Elijah23Johnson]

+1
Same error
"react-native": "0.61.5"