Add native iOS notifications (#64)

ios/Info.plist

@@ -2,6 +2,10 @@
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
 <dict>
+	<key>BGTaskSchedulerPermittedIdentifiers</key>
+	<array>
+		<string>de.rfc1437.gotcha.notifications.refresh</string>
+	</array>
 	<key>CFBundleDevelopmentRegion</key>
 	<string>$(DEVELOPMENT_LANGUAGE)</string>
 	<key>CFBundleDisplayName</key>
@@ -33,6 +37,10 @@
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<key>ITSAppUsesNonExemptEncryption</key>
 	<false/>
+	<key>UIBackgroundModes</key>
+	<array>
+		<string>fetch</string>
+	</array>
 	<key>UILaunchScreen</key>
 	<dict/>
 	<key>UISupportedInterfaceOrientations</key>