Exclude local Bundler config directory from VC

Ref: react-native-community/template#209

Author: leotm

.gitignore

@@ -59,6 +59,7 @@ yarn-error.log
 # Ruby / CocoaPods
 **/Pods/
 /vendor/bundle/
+/.bundle/
 
 # Temporary files created by Metro to check the health of the file watcher
 .metro-health-check*