issue #89 default user permissions are now set when using drush install

[tabroughton]

this code is taken from the manual install but it wasn't included in the drush install for some reason. I believe it is required though as it is the default behaviour for setting permissions when installing manually, without this the admin needs to set up the permissions within the UI after it has been installed.

[civicrm-builder]

Can one of the admins verify this patch?

[civibot]

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[herbdool]

I think this makes sense so I think it can be merged.

By the way, I'm not sure how many people are installing via drush. There is also a CiviCRM CLI tool called cv (which I haven't used). Might want to give it a spin too since it's kept more up to date. I'm not sure if it helps with the install part.