Move apache-rat configuration from site to pluginManagement section, so that it also applies when "mvn apache-rat:check" is run.

Remove exclusion of git files from apache-rat configuration, as these files are excluded by default.
diff --git a/pom.xml b/pom.xml
index cfe9395..18a1082 100644
--- a/pom.xml
+++ b/pom.xml
@@ -195,6 +195,19 @@
             </tags>
           </configuration> 
         </plugin>
+        <plugin>
+          <groupId>org.apache.rat</groupId>
+          <artifactId>apache-rat-plugin</artifactId>
+          <version>${commons.rat.version}</version>
+          <configuration>
+            <excludes>
+              <!-- files used during tests -->
+              <exclude>src/test/resources/**</exclude>
+              <exclude>.pmd</exclude>
+              <exclude>.projectile</exclude>
+            </excludes>
+          </configuration>
+        </plugin>
       </plugins>
     </pluginManagement>
     <plugins>
@@ -310,21 +323,6 @@
           <excludeFilterFile>${basedir}/findbugs-exclude-filter.xml</excludeFilterFile>
        </configuration>
       </plugin>
-      <plugin>
-        <groupId>org.apache.rat</groupId>
-        <artifactId>apache-rat-plugin</artifactId>
-        <version>${commons.rat.version}</version>
-        <configuration>
-          <excludes>
-            <!-- files used during tests -->
-            <exclude>src/test/resources/**</exclude>
-            <exclude>.pmd</exclude>
-            <exclude>.gitignore</exclude>
-            <exclude>.gitattributes</exclude>
-            <exclude>.projectile</exclude>
-          </excludes>
-        </configuration>
-      </plugin>
     </plugins>
   </reporting>