upgrade slf4j version

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-components/trunk@1591518 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index f75efc2..7c4964a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -38,7 +38,7 @@
   <properties>
     <commons-configuration.version>1.9</commons-configuration.version>
     <commons-lang.version>2.6</commons-lang.version>
-    <slf4jVersion>1.7.5</slf4jVersion>
+    <slf4jVersion>1.7.7</slf4jVersion>
     <log4jVersion>2.0-rc1</log4jVersion>
     <springVersion>4.0.2.RELEASE</springVersion>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>