TEZ-4288: Upgrade SLF4J to 1.7.30 (#109)

Author: belugabehr

pom.xml

@@ -62,7 +62,7 @@
     <netty.version>3.10.5.Final</netty.version>
     <pig.version>0.13.0</pig.version>
     <jersey.version>1.19</jersey.version>
-    <slf4j.version>1.7.10</slf4j.version>
+    <slf4j.version>1.7.30</slf4j.version>
     <protobuf.version>2.5.0</protobuf.version>
     <protoc.path>${env.PROTOC_PATH}</protoc.path>
     <scm.url>scm:git:https://gitbox.apache.org/repos/asf/tez.git</scm.url>