add .gitignore

+# Xcode
+#
+# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
+
+## Build generated
+build/
+DerivedData/
+
+## Various settings
+*.pbxuser
+!default.pbxuser
+*.mode1v3
+!default.mode1v3
+*.mode2v3
+!default.mode2v3
+*.perspectivev3
+!default.perspectivev3
+xcuserdata/
+xcshareddata/
+contents.xcworkspacedata
+
+## Other
+*.moved-aside
+*.xcuserstate
+
+## Obj-C/Swift specific
+*.hmap
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+# CocoaPods
+#
+# We recommend against adding the Pods directory to your .gitignore. However
+# you should judge for yourself, the pros and cons are mentioned at:
+# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
+#
+Pods/
+
+# Carthage
+#
+# Add this line if you want to avoid checking in source code from Carthage dependencies.
+Carthage
+
+# fastlane
+#
+# It is recommended to not store the screenshots in the git repo. Instead, use fastlane to re-generate the 
+# screenshots whenever they are needed.
+# For more information about the recommended setup visit:
+# https://github.com/fastlane/fastlane/blob/master/fastlane/docs/Gitignore.md
+
+fastlane/report.xml
+fastlane/screenshots
+.DS_Store
+Scripts/
+Build/
+#ExportOptions.plist