fix(package): update react-native-maps to version 0.15.3

Author: greenkeeper[bot]

package.json

@@ -78,7 +78,7 @@
     "react-native-google-analytics-bridge": "5.1.0",
     "react-native-keychain": "1.2.0",
     "react-native-linear-gradient": "2.0.0",
-    "react-native-maps": "0.15.2",
+    "react-native-maps": "0.15.3",
     "react-native-network-info": "2.2.0",
     "react-native-onesignal": "3.0.4",
     "react-native-parallax-view": "2.0.6",