chore(package): update lockfile

https://npm.im/greenkeeper-lockfile

Author: greenkeeperio-bot

yarn.lock

@@ -5973,9 +5973,9 @@ react-navigation-tabs@^0.4.0:
     react-native-safe-area-view "^0.7.0"
     react-native-tab-view "^1.0.0"
 
-react-navigation@2.10.0:
-  version "2.10.0"
-  resolved "https://registry.yarnpkg.com/react-navigation/-/react-navigation-2.10.0.tgz#b525821261bedb3b4d3ee91564cad32fca2bd684"
+react-navigation@2.11.2:
+  version "2.11.2"
+  resolved "https://registry.yarnpkg.com/react-navigation/-/react-navigation-2.11.2.tgz#cd099f6d7d09efe48ef8463614a3abb113d45c01"
   dependencies:
     clamp "^1.0.1"
     create-react-context "^0.2.1"