fix(package): update react-native-maps to version 0.16.4

Author: greenkeeper[bot]

package.json

@@ -74,7 +74,7 @@
     "react-native-google-analytics-bridge": "5.3.3",
     "react-native-keychain": "2.0.0-rc",
     "react-native-linear-gradient": "2.3.0",
-    "react-native-maps": "0.16.3",
+    "react-native-maps": "0.16.4",
     "react-native-network-info": "2.2.0",
     "react-native-onesignal": "3.0.5",
     "react-native-restart": "0.0.3",