HADOOP-17236. Bump up snakeyaml to 1.26 to mitigate CVE-2017-18640. Contributed by Brahma Reddy Battula.

Signed-off-by: Wei-Chiu Chuang <weichiu@apache.org>

hadoop-project/pom.xml

@@ -199,7 +199,7 @@
     <declared.hadoop.version>${hadoop.version}</declared.hadoop.version>
 
     <swagger-annotations-version>1.5.4</swagger-annotations-version>
-    <snakeyaml.version>1.16</snakeyaml.version>
+    <snakeyaml.version>1.26</snakeyaml.version>
     <hbase.one.version>1.4.8</hbase.one.version>
     <hbase.two.version>2.0.2</hbase.two.version>
     <junit.version>4.12</junit.version>