Remove pending specs for methods that dont exist (#1658)

* Remote spec for non-existent entry_classes helper method

This method no longer exists, and is handled by a local variable in a partial
instead.

* Remove spec for non-existent Account#ping! method

spec/helpers/stream_entries_helper_spec.rb

@@ -14,8 +14,4 @@ RSpec.describe StreamEntriesHelper, type: :helper do
       expect(helper.display_name(account)).to eq "Username"
     end
   end
-
-  describe '#entry_classes' do
-    pending
-  end
 end

spec/models/account_spec.rb

@@ -118,10 +118,6 @@ RSpec.describe Account, type: :model do
     end
   end
 
-  describe '#ping!' do
-    pending
-  end
-
   describe '#favourited?' do
     let(:original_status) do
       author = Fabricate(:account, username: 'original')