missing a $ in appc-directed-graph pom

Change-Id: I51eaa20c5db47c50e7cc8ffc9f53d7f01bc54c33
Issue-ID: APPC-774
Signed-off-by: Taka Cho <tc012c@att.com>
diff --git a/appc-directed-graph/pom.xml b/appc-directed-graph/pom.xml
index ec0aaec..345f2c8 100644
--- a/appc-directed-graph/pom.xml
+++ b/appc-directed-graph/pom.xml
@@ -102,7 +102,7 @@
             <dependency>
                 <groupId>commons-collections</groupId>
                 <artifactId>commons-collections</artifactId>
-                <version>{commons.collections.version}</version>
+                <version>${commons.collections.version}</version>
             </dependency>
             <dependency>
                 <groupId>commons-io</groupId>