used version from parent pom

ethereum/pom.xml

@@ -177,8 +177,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>${compiler.plugin.version}</version>
                 <configuration>
-                    <source>${source.version}</source>
-                    <target>${target.version}</target>
+                    <source>${java.version}</source>
+                    <target>${java.version}</target>
                 </configuration>
             </plugin>
             <plugin>
@@ -189,7 +189,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-war-plugin</artifactId>
-                <version>${war.plugin.version}</version>
+                <version>${maven-war-plugin.version}</version>
                 <configuration>
                     <warSourceDirectory>src/main/webapp</warSourceDirectory>
                     <failOnMissingWebXml>false</failOnMissingWebXml>
@@ -216,8 +216,5 @@
         <slf4j.version>1.7.25</slf4j.version>
         <spring-boot-maven-plugin.version>2.0.4.RELEASE</spring-boot-maven-plugin.version>
         <compiler.plugin.version>3.1</compiler.plugin.version>
-        <source.version>1.8</source.version>
-        <target.version>1.8</target.version>
-        <war.plugin.version>3.0.0</war.plugin.version>
     </properties>
 </project>