Create tic-tac-toe.js in React (hacktoberfest17#997)

Create call_by_reference.pl (hacktoberfest17#737)

* Add is_palindrome.pl

Added Perl-script to find if a string is palindromic or not.

* delete is_palindrome.pl

adding subfolder

* add perl folder, create is_palindrome.pl

Perl-script for checking palindrome

* Create call_by_reference.pl

Added perl-script to show calling by reference in perl

Merge pull request hacktoberfest17#546 from hacktoberfest17/anurag-fi…

…xes-1

Anurag fixes 1

Merge pull request hacktoberfest17#445 from EshraqIbrahim/master

added Tic-tac-toe in java

Merge pull request hacktoberfest17#232 from TheHungryBu/thehungrybu_h…

…ello_world_in_lisp

Add Hello world in lisp (closes hacktoberfest17#231)

Merge pull request hacktoberfest17#15 from hacktober17/anurag-contrib…

…uting

Update CONTRIBUTING.md