Bumped version of gRPC to 1.3.1

Change-Id: I7798476bd443a796e0e6a6e149ab8f66435ba4fa
diff --git a/protocols/grpc/api/pom.xml b/protocols/grpc/api/pom.xml
index 49e42c6..af2a8c5 100644
--- a/protocols/grpc/api/pom.xml
+++ b/protocols/grpc/api/pom.xml
@@ -46,8 +46,8 @@
        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-stub</artifactId>
-           <version>1.3.0</version>
+           <version>1.3.1</version>
        </dependency>
    </dependencies>
 
-</project>
\ No newline at end of file
+</project>