add system tests for updating dietary restrictions

add system tests to cover a member updating their details to add/remove
dietary restrictions.

Author: mikej

spec/features/member_updating_details_spec.rb

@@ -0,0 +1,46 @@
+RSpec.feature 'Update your details', type: :feature do
+  before do
+    mock_github_auth
+  end
+
+  scenario 'A member adds a dietary restriction' do
+    member = Fabricate(:member)
+    login member
+
+    visit edit_member_path
+    check 'Vegetarian'
+    click_on 'Save'
+
+    expect(page).to have_content('Your details have been updated.')
+    expect(page).to have_selector(".badge", text: "Vegetarian")
+  end
+
+  scenario 'A member adds a custom dietary restriction' do
+    member = Fabricate(:member)
+    login member
+
+    visit edit_member_path
+    check 'Other'
+    fill_in 'Other dietary restrictions', with: 'peanut allergy'
+    click_on 'Save'
+
+    expect(page).to have_content('Your details have been updated.')
+    expect(page).to have_selector(".badge", text: "Peanut allergye")
+    member.reload
+    expect(member.dietary_restrictions).to eq(['other'])
+    expect(member.other_dietary_restrictions).to eq('peanut allergy')
+  end
+
+  scenario 'A member removes a dietary restriction' do
+    member = Fabricate(:member, dietary_restrictions: ['vegetarian'])
+    login member
+
+    visit edit_member_path
+    uncheck 'Vegetarian'
+    click_on 'Save'
+
+    expect(page).to have_content('Your details have been updated.')
+    member.reload
+    expect(member.dietary_restrictions).to be_empty
+  end
+end