perf: Remove unused properties in pom.xml (#26)

1. Remove arg.line properties
2. Extract maven.resource.version properties

see issue: #25

Author: pinxiong

pom.xml

@@ -79,12 +79,9 @@
         <checkstyle.version>3.1.2</checkstyle.version>
         <apache.rat.version>0.13</apache.rat.version>
         <cobertura.maven.version>2.7</cobertura.maven.version>
+        <maven.resources.version>3.2.0</maven.resources.version>
         <maven.surefire.version>3.0.0-M1</maven.surefire.version>
         <maven.jacoco.version>0.8.6</maven.jacoco.version>
-        <!-- Build args -->
-        <arg.line>-server -Xms256m -Xmx512m -Dfile.encoding=UTF-8
-            -Djava.net.preferIPv4Stack=true -XX:MetaspaceSize=64m -XX:MaxMetaspaceSize=128m
-        </arg.line>
         <checkstyle.skip>true</checkstyle.skip>
         <rat.skip>true</rat.skip>
         <jacoco.skip>true</jacoco.skip>
@@ -189,7 +186,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-resources-plugin</artifactId>
-                <version>3.2.0</version>
+                <version>${maven.resources.version}</version>
                 <configuration>
                     <encoding>UTF-8</encoding>
                 </configuration>