Merge pull request #74 from jvm-operators/slf4j-version-align

slf4j version align w/ spark

Author: jkremser

pom.xml

@@ -77,7 +77,7 @@
         <prometheus.metrics.version>0.6.0</prometheus.metrics.version>
         <guava.version>23.0</guava.version>
         <snakeyaml.version>1.24</snakeyaml.version>
-        <slf4j.version>1.7.26</slf4j.version>
+        <slf4j.version>1.7.16</slf4j.version>
         <junit.version>4.12</junit.version>
     </properties>
     <dependencyManagement>