Add js to post_process_dist.sh.

Change-Id: I1ee87c49481bcc545939745ccf0a53d766a01a4c

post_process_dist.sh

@@ -27,7 +27,7 @@ fi
 
 set -ex
 
-LANGUAGES="cpp csharp java javanano objectivec python ruby"
+LANGUAGES="cpp csharp java javanano js objectivec python ruby"
 BASENAME=`basename $1 .tar.gz`
 VERSION=${BASENAME:9}