Use JavaScript in system tests by default

JavaScript is used by about 98% of web users, so by testing without it
enabled, we're only testing that the application works for a very
reduced number of users.

We proceeded this way in the past because CONSUL started using Rails 4.2
and truncating the database between JavaScript tests with database
cleaner, which made these tests terribly slow.

When we upgraded to Rails 5.1 and introduced system tests, we started
using database transactions in JavaScript tests, making these tests much
faster. So now we can use JavaScript tests everywhere without critically
slowing down our test suite.

spec/system/admin/administrators_spec.rb

@@ -18,7 +18,7 @@ describe "Admin administrators" do
     expect(page).not_to have_content user.name
   end
 
-  scenario "Create Administrator", :js do
+  scenario "Create Administrator" do
     fill_in "search", with: user.email
     click_button "Search"
 
@@ -29,7 +29,7 @@ describe "Admin administrators" do
     end
   end
 
-  scenario "Delete Administrator", :js do
+  scenario "Delete Administrator" do
     within "#administrator_#{user_administrator.id}" do
       accept_confirm { click_link "Delete" }
     end
@@ -39,7 +39,7 @@ describe "Admin administrators" do
     end
   end
 
-  scenario "Delete Administrator when its the current user", :js do
+  scenario "Delete Administrator when its the current user" do
     within "#administrator_#{admin.id}" do
       accept_confirm { click_link "Delete" }
     end
@@ -101,7 +101,7 @@ describe "Admin administrators" do
       expect(page).not_to have_content(administrator1.email)
     end
 
-    scenario "Delete after searching", :js do
+    scenario "Delete after searching" do
       fill_in "Search user by name or email", with: administrator2.email
       click_button "Search"