'com.onesignal:OneSignal:2.1.1'
<dependency>
<groupId>com.onesignal</groupId>
<artifactId>OneSignal</artifactId>
<version>2.1.1</version>
</dependency>
<dependency org="com.onesignal" name="OneSignal" rev="2.1.1"/>
"com.onesignal", "OneSignal", "2.1.1"