DS-2231 Don't echo create-administrator password

https://jira.duraspace.org/browse/DS-2231
Uses console.readPassword(), to not echo the user's password when they create a user on the command line.

```
peterdietz:DSPACE5 peterdietz$ /dspace/bin/dspace create-administrator
Creating an initial administrator account
E-mail address: peter2@domain.com
First name: Peter2
Last name: Dietz2
Password will not display on screen.
Password: 
Again to confirm: 
Is the above data correct? (y or n): y
Administrator account created
```