Added jrnl formula

Hi there, 

I added a new formula for [jrnl](http://maebert.github.io/jrnl/) following your `contributing` guidelines.
It installs on a mavericks host and runs the test correctly.

If possible, please merge.

Thanks for your work.
Apparently if I do -v it will check for dependencies, so I'll change this for testing: https://github.com/maebert/jrnl/issues/286#issuecomment-57347643

I'll add this to the PR tomorrow