Add missing plugin versions to LC pom (#910)

Author: bullet-tooth

exonum-light-client/pom.xml

@@ -359,6 +359,7 @@
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-gpg-plugin</artifactId>
+            <version>1.6</version>
             <executions>
               <execution>
                 <id>sign-artifacts</id>
@@ -380,6 +381,7 @@
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-deploy-plugin</artifactId>
+            <version>2.8.2</version>
             <executions>
               <execution>
                 <id>default-deploy</id>