adds functionality to cd and made function to display current directory.
error fix
Merge pull request #3 from NathanBland/master

Merge pull request #1 from Dameier/master
Our current work on fork and exec
exec in s now working, needs env variable
commiting working exec function
Merge branch 'master' of https://github.com/Dameier/shellND
Merge pull request #2 from Dameier/master

Massive update to my branch