roll back the logback version

Change-Id: I34661e29c605b7731c92412d9c0c57c91583e8a4
Issue-ID: APPC-684
Signed-off-by: Taka Cho <tc012c@att.com>
diff --git a/appc-directed-graph/dg-loader/pom.xml b/appc-directed-graph/dg-loader/pom.xml
index 26c459e..02ef801 100644
--- a/appc-directed-graph/dg-loader/pom.xml
+++ b/appc-directed-graph/dg-loader/pom.xml
@@ -45,7 +45,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <java.version.source>1.8</java.version.source>
         <java.version.target>1.8</java.version.target>
-        <logback.version>1.2.3</logback.version>
+        <logback.version>1.1.1</logback.version>
         <commons.collections.version>3.2.2</commons.collections.version>
         <common.io.version>2.5</common.io.version>
         <jettison.version>1.3.7</jettison.version>