chore(package): update react-native-screens in group default to the latest version (#1524)

Author: greenkeeper[bot]

example/package.json

@@ -30,7 +30,7 @@
     "react-native-reanimated": "~1.4.0",
     "react-native-safe-area-context": "0.6.0",
     "react-native-safe-area-view": "^0.12.0",
-    "react-native-screens": "2.0.0-alpha.18",
+    "react-native-screens": "2.0.0-alpha.19",
     "react-native-vector-icons": "^6.6.0",
     "react-native-web": "^0.11.7",
     "typeface-roboto": "^0.0.54"

example/yarn.lock

@@ -10114,10 +10114,10 @@ react-native-safe-area-view@^0.12.0:
   dependencies:
     hoist-non-react-statics "^2.3.1"
 
-[email protected].18:
-  version "2.0.0-alpha.18"
-  resolved "https://registry.yarnpkg.com/react-native-screens/-/react-native-screens-2.0.0-alpha.18.tgz#70c116cc96069ad1d930f2984bbec7d66856a1ee"
-  integrity sha512-ML5MVFMWsw7x4GdAA6xWMnFUp37Rk4dpNb5MKrRIPqOTYTS+cN+eyo7UCqICEa6KwYKCtGN6Kq7xrKOtboWPMg==
+[email protected].19:
+  version "2.0.0-alpha.19"
+  resolved "https://registry.yarnpkg.com/react-native-screens/-/react-native-screens-2.0.0-alpha.19.tgz#6af901a4061d384d6a6c1b4aae13a9b156e6f17e"
+  integrity sha512-lTzuSQMwyvOcb4pXbNiHkyd1IZRH1e9wMtI8etsF+WPwP+I0K/vdxn3tgSCT5WbX2EyuEArFH3NUfXLmBota8w==
   dependencies:
     debounce "^1.2.0"