JSIEVE-112 Replace log4j by logback-classic
diff --git a/core/pom.xml b/core/pom.xml
index c3952cf..ba74dbb 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -63,8 +63,8 @@
         </dependency>
 
         <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-core</artifactId>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
             <scope>test</scope>
         </dependency>
 
diff --git a/pom.xml b/pom.xml
index 0aa8147..7f90aa1 100644
--- a/pom.xml
+++ b/pom.xml
@@ -78,7 +78,7 @@
 
         <junit.version>4.12</junit.version>
         <jmock.version>1.2.0</jmock.version>
-        <log4j.version>2.12.1</log4j.version>
+        <logback.version>1.2.3</logback.version>
         <mail.version>1.4.7</mail.version>
         <activation.version>1.1.1</activation.version>
         <commons-io.version>2.1</commons-io.version>
@@ -134,8 +134,8 @@
                         <artifactId>logkit</artifactId>
                     </exclusion>
                     <exclusion>
-                        <groupId>org.apache.logging.log4j</groupId>
-                        <artifactId>log4j-core</artifactId>
+                        <groupId>ch.qos.logback</groupId>
+                        <artifactId>logback-classic</artifactId>
                     </exclusion>
                     <exclusion>
                         <groupId>javax.servlet</groupId>
@@ -156,9 +156,9 @@
                 <scope>test</scope>
             </dependency>
             <dependency>
-                <groupId>org.apache.logging.log4j</groupId>
-                <artifactId>log4j-core</artifactId>
-                <version>${log4j.version}</version>
+                <groupId>ch.qos.logback</groupId>
+                <artifactId>logback-classic</artifactId>
+                <version>${logback.version}</version>
                 <scope>test</scope>
             </dependency>
             <dependency>
diff --git a/util/pom.xml b/util/pom.xml
index 0d63d95..ac483e1 100644
--- a/util/pom.xml
+++ b/util/pom.xml
@@ -70,8 +70,8 @@
         </dependency>
 
         <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-core</artifactId>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
             <scope>test</scope>
         </dependency>