MINDEXER-91: Add a Spring based example

- Committing forgotten change to parent pom.xml.
diff --git a/pom.xml b/pom.xml
index b60fbab..788d510 100644
--- a/pom.xml
+++ b/pom.xml
@@ -108,6 +108,26 @@
         <artifactId>slf4j-api</artifactId>
         <version>1.7.5</version>
       </dependency>
+      <dependency>
+        <groupId>ch.qos.logback</groupId>
+        <artifactId>logback-classic</artifactId>
+        <version>1.1.2</version>
+        <scope>optional</scope>
+      </dependency>
+      <dependency>
+        <groupId>ch.qos.logback</groupId>
+        <artifactId>logback-core</artifactId>
+        <version>1.1.2</version>
+        <scope>optional</scope>
+      </dependency>
+      <dependency>
+        <!-- This dependency is required in order to intercept Spring logging and handle it through Logback + SLF4J,
+             as it would otherwise use commons-logging and do it's own other thing. -->
+        <groupId>org.slf4j</groupId>
+        <artifactId>jcl-over-slf4j</artifactId>
+        <version>1.7.7</version>
+        <scope>optional</scope>
+      </dependency>
 
       <dependency>
         <groupId>com.google.guava</groupId>