elisp: adding .cask files to gitignore
elisp: adding .cask files to gitignore

cask is a dependency/package management tool for Emacs lisp packages. Adding
.cask to gitignore template to avoid tracking of installed packages not
a part of repository

bruennijs/ise.cppworkshop,szymanskirafal/gitignore,bruennijs/ise.cppworkshop,bruennijs/ise.cppworkshop,chhsieh/helloworld,chhsieh/gitTest_1,szymanskirafal/gitignore,szymanskirafal/gitignore