[CALCITE-3090] Remove the Central configuration

We don't actually need the explicit configuration for Central. We're
just providing the same value that's already configured.

Closes #100

Signed-off-by: Kevin Risden <krisden@apache.org>
diff --git a/pom.xml b/pom.xml
index a4c1962..83a5d8b 100644
--- a/pom.xml
+++ b/pom.xml
@@ -733,17 +733,6 @@
       </plugin>
     </plugins>
   </reporting>
-  <repositories>
-    <repository>
-      <id>central</id>
-      <name>Central Repository</name>
-      <url>http://repo.maven.apache.org/maven2</url>
-      <layout>default</layout>
-      <snapshots>
-        <enabled>false</enabled>
-      </snapshots>
-    </repository>
-  </repositories>
   <profiles>
     <profile>
       <!-- This profile adds/overrides few features of the 'apache-release'