pom fix around gNMI

Change-Id: I6cd5190e7a9daa3d9050893d7b6195a01e549090
diff --git a/incubator/grpc-dependencies/pom.xml b/incubator/grpc-dependencies/pom.xml
index 7ad4a10..98a8c8f 100644
--- a/incubator/grpc-dependencies/pom.xml
+++ b/incubator/grpc-dependencies/pom.xml
@@ -30,8 +30,8 @@
     <packaging>pom</packaging>
 
     <properties>
-        <grpc.version>1.2.0</grpc.version>
-        <grpc.package.version>1.2.0</grpc.package.version>
+        <grpc.version>1.3.1</grpc.version>
+        <grpc.package.version>1.3.1</grpc.package.version>
         <grpc.netty.version>4.1.8.Final</grpc.netty.version>
         <grpc.netty.package.version>4.1.8</grpc.netty.package.version>
         <google.auth.version>0.4.0</google.auth.version>