Read only accounts should be able to hit the add button

[fatboypunk]

Now it breaks when i want to go to
http://zfsstats.jeroen92.nl/servers/new
http://zfsstats.jeroen92.nl/users/5392dde2706c2d1d4dba0100/edit
http://zfsstats.jeroen92.nl/users/new
with the read only account

[jeroen92]

I modified the available privileges for the demo application since I didn't want everyone on the internet to be able to change the demo user's password. If you would clone the repo then you won't have this limitation. The read-only user should really be read-only, so it's normal behaviour a read-only account can't add servers or users. You'll need some more privileges in order to do that.

Of course the result should be something prettier as it looks like an 500 internal server error at the moment :-)