GH-28 Add auto remove whitelisted ips when using only ee auth delete <sitename>

[PiyushKhurana]

Fixes #28

Approach

Since there is already a different code to handle the case when we provide --ip option , therefore we have to handle it in the normal case.
I have checked for a particular condition which is when user only execute ee auth delete <sitename> command.

NOTE: since it was design earlier to delete auths only , and user specific auths also , so there is possibility that user can pass a username , that is why we have to check for the above condition

Now in this condition , we will be deleting whitelisted ips along with deleting the auths.
We have to first delete whitelisted ips if any because , it doesn't throw any error if there are no whitelisted ips already.
Deleting auths first will hault the code execution when there are no auths on the site as it will throw a error.