Android Build Error :Unable to merge manifest

We are using Appwarp and facebook in our project and merging admob(Prime31)into the existing project but on making build it always throws error:

**1**Error building Player: CommandInvokationFailure: Unable to merge android manifests. See the Console for more details. /Library/Java/JavaVirtualMachines/jdk1.8.0_72.jdk/Contents/Home/bin/java -Xmx2048M -Dcom.android.sdkmanager.toolsdir="/Volumes/Important/adt-bundle-mac-x86_64-20131030 2/sdk/tools" -Dfile.encoding=UTF8 -jar "/Applications/Unity 4.6/Unity.app/Contents/BuildTargetTools/AndroidPlayer/sdktools.jar

**2**Trying to merge incompatible /manifest/application/meta-data[@name=com.google.android.gms.version] element:

UnityEditor.HostView:OnGUI()

Any help would be great