Added missing datanucleus-core dependency in main dependencies section.

Review at http://gwt-code-reviews.appspot.com/833801

Review by: drfibonacci@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@8695 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/samples/expenses/pom.xml b/samples/expenses/pom.xml
index 39eca1a..e9ac822 100644
--- a/samples/expenses/pom.xml
+++ b/samples/expenses/pom.xml
@@ -164,6 +164,18 @@
             <artifactId>datanucleus-appengine</artifactId>
             <version>1.0.7.final</version>
         </dependency>
+        <!-- must be in main dependencies as well as plugin dependencies below -->
+        <dependency>
+            <groupId>org.datanucleus</groupId>
+            <artifactId>datanucleus-core</artifactId>
+            <version>${datanucleus.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>javax.transaction</groupId>
+                    <artifactId>transaction-api</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
     <dependency>
             <groupId>com.google.appengine</groupId>
             <artifactId>appengine-api-1.0-sdk</artifactId>