Add ability to pipe STDIN to cron tasks

In case the container expects input.

Signed-off-by: Dan Buch <d.buch@modcloth.com>
Add modcloth_app_cron_stdin_command to README
Fleshed out description of modcloth_app_cron_stdin_command
Merge remote-tracking branch 'origin/master' into add-stdin-to-cron-wrapper

Conflicts:
	templates/cron-wrapper.sh.j2
Merge pull request #15 from modcloth/add-stdin-to-cron-wrapper

Add ability to pipe STDIN to cron tasks