Tried to add some basic automation for adding my ssh-keys to an ssh-agent

Not complete yet however - TODO
 - check if ssh-agent is running
 - check if hal_rsa has already been added to the ssh-agent
Merge remote-tracking branch 'refs/remotes/origin/jn-little' into new-master
Added a $HOME/bin directory to my path
Had to temporarily disable automatic ssh-add from zshenv - it was called ALL the time.....need to figure out a way to call only once - check value of 'ssh-add -l'?