KNOX-2175 - Upgrade slf4j to 1.7.30

Signed-off-by: Kevin Risden <krisden@apache.org>
diff --git a/pom.xml b/pom.xml
index f61c930..ae36dd3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -239,7 +239,7 @@
         <shiro.version>1.4.2</shiro.version>
         <shrinkwrap.version>1.2.6</shrinkwrap.version>
         <shrinkwrap.descriptors.version>2.0.0</shrinkwrap.descriptors.version>
-        <slf4j.version>1.7.29</slf4j.version>
+        <slf4j.version>1.7.30</slf4j.version>
         <spotbugs.version>3.1.12</spotbugs.version>
         <spotbugs-maven-plugin.version>3.1.12.2</spotbugs-maven-plugin.version>
         <spring-core.version>5.2.1.RELEASE</spring-core.version>