Configure postgres permissions

Craig tested this script on Ubunty 14.04 Trusty and reports that because does not configure Postgres permissions, db:setup etc will not work.

A couple of ways to tackle this. Either create a superuser in your name:

```
[0:12] Paul McCulloch: I was looking at some of the install scripts to help me figure out pg install and found this allowed no mod of pg_hba.conf:
`sudo -u postgres createuser --superuser paul`

[7:08] David Corking: http://www.postgresql.org/docs/9.1/static/app-createuser.html
```

or

edit pg_hba.conf as we do in the LocalSupport and vagrant scripts (thanks to @tansaku )

```
# needs work to handle variable white space
#
sudo sed -i -e 's/local\s\+all\s\+postgres\s\+peer/local all postgres peer map=basic/g' /etc/postgresql/9.1/main/pg_hba.conf
```

Which approach shall we choose?