Bump commons-io from 2.4 to 2.7 in /markbook

Bumps commons-io from 2.4 to 2.7.

---
updated-dependencies:
- dependency-name: commons-io:commons-io
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/markbook/pom.xml b/markbook/pom.xml
index 166fa6d..9a61518 100644
--- a/markbook/pom.xml
+++ b/markbook/pom.xml
@@ -66,7 +66,7 @@
         <dependency>
             <groupId>commons-io</groupId>
             <artifactId>commons-io</artifactId>
-            <version>2.4</version>
+            <version>2.7</version>
         </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>