.travis/fix_java_format.sh: add --diff flag and output on number of files
.travis/fix_java_format.sh: add --diff flag and output on number of files

batfish/batfish,arifogel/batfish,intentionet/batfish,arifogel/batfish,intentionet/batfish,batfish/batfish,dhalperi/batfish,intentionet/batfish,intentionet/batfish,intentionet/batfish,dhalperi/batfish,dhalperi/batfish,batfish/batfish,arifogel/batfish