Changes to specs to remove deprecated syntax

This pull request contains changes to various tests to replace deprecated Rspec syntax with the recommended form.

Most of the changes are switching from `be_false` or `be_true` to `be false` or `be true`.
There are some changes from `should` to `expect`  - mostly of the form 
`should have(n).items`  to  `expect(thing.size).to eq(n)`
Expect syntax can take a block, so this should be
```ruby
expect { user.add_role(:new_role) }.to change(user.roles, :count).by(1)
```

Same goes for the other one in this file.