Adding the possibility to specify an AdminUser

[EtienneDepaulis]

Hello guys,

on our app we have a User model for our users and an AdminUser model for our admin users. This PR adds the possibility to specify this behavior in the configuration:

PolicyManager::Config.setup do |c|
  c.admin_user_resource = AdminUser
end

PolicyManager::UserTermsController.send(:include, Devise::Controllers::Helpers)

I had to fix the display of the navbar as when you are logged in as an AdminUser you don't have any terms to accept (which is a common user action).

Todo :

• [ ] Update Readme
• [ ] Update all User direct usage instead of Config.user_resource (fixed one in the exporter)

I've also taken the liberty to:

• remove mysql2 version restriction
• remove all coverage files which should not be versioned (and updated gitignore)

What do you think of this feature ?

[coveralls]

Pull Request Test Coverage Report for Build 30

• 5 of 9 (55.56%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.5%) to 93.056%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/policy_manager/config.rb	4	8	50.0%
<!--	Total:	5	9	55.56%	-->

Files with Coverage Reduction	New Missed Lines	%
test/dummy/app/models/user.rb	1	55.56%
<!--	Total:	1		-->

Totals
Change from base Build 28:	-0.5%
Covered Lines:	737
Relevant Lines:	792

---

💛 - Coveralls

[michelson]

Hi @EtienneDepaulis , this is a great addition to the library. I will test this in our implementation before merge, but overall it looks good to me. best!