Fix build

Looks like we lost a method that I was using in a test when merging
master. Oops! This fixes the build and lets us move forward.

Author: nik9000

server/src/main/java/org/elasticsearch/common/time/FormatNames.java

@@ -111,4 +111,8 @@ public enum FormatNames {
     public boolean matches(String format) {
         return format.equals(snakeCaseName);
     }
+
+    public String getSnakeCaseName() {
+        return snakeCaseName;
+    }
 }