Fix plugin version missing bug.

pom.xml

@@ -117,6 +117,7 @@
         <findbugs-maven-plugin.version>3.0.2</findbugs-maven-plugin.version>
         <maven-checkstyle-plugin.version>2.16</maven-checkstyle-plugin.version>
         <maven-pmd-plugin.version>3.5</maven-pmd-plugin.version>
+        <frontend-maven-plugin.version>1.8.0</frontend-maven-plugin.version>
         <jdepend-maven-plugin.version>2.0</jdepend-maven-plugin.version>
         <taglist-maven-plugin.version>2.4</taglist-maven-plugin.version>
         <maven-gpg-plugin.version>1.6</maven-gpg-plugin.version>

sharding-ui/sharding-ui-frontend/pom.xml

@@ -35,6 +35,7 @@
             <plugin>
                 <groupId>com.github.eirslett</groupId>
                 <artifactId>frontend-maven-plugin</artifactId>
+                <version>${frontend-maven-plugin.version}</version>
                 <executions>
                     <execution>
                         <id>install node and npm</id>